U.S. patent number 10,800,868 [Application Number 16/690,185] was granted by the patent office on 2020-10-13 for antifouling film and polymerizable composition.
This patent grant is currently assigned to SHARP KABUSHIKI KAISHA. The grantee listed for this patent is Sharp Kabushiki Kaisha. Invention is credited to Kenichiro Nakamatsu, Yasuhiro Shibai, Tokio Taguchi.
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United States Patent |
10,800,868 |
Shibai , et al. |
October 13, 2020 |
Antifouling film and polymerizable composition
Abstract
An antifouling film includes: a substrate; and a polymer layer
disposed on a surface of the substrate and including on a surface
thereof an uneven structure provided with projections at a pitch
not longer than a wavelength of visible light. The polymer layer is
a cured product of a polymerizable composition. The polymerizable
composition contains, in terms of active components, 75 to 95 wt %
of a polymerizable monomer, 2.5 to 12.5 wt % of a urethane acrylate
containing fluorine and an ester, and 2.5 to 9 wt % of a
perfluoroalkyl-based monomer containing one (meth)acryloyl group
for each molecule. The polymerizable monomer contains a
bifunctional acrylate that contains an ethylene oxide group and a
multifunctional acrylate that contains no ethylene oxide group. The
perfluoroalkyl-based monomer has a fluorine atom concentration of
50 to 60 wt %. The polymerizable composition has an ethylene oxide
group concentration of 20 to 50 wt %.
Inventors: |
Shibai; Yasuhiro (Sakai,
JP), Taguchi; Tokio (Sakai, JP), Nakamatsu;
Kenichiro (Sakai, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Sharp Kabushiki Kaisha |
Sakai, Osaka |
N/A |
JP |
|
|
Assignee: |
SHARP KABUSHIKI KAISHA (Sakai,
JP)
|
Family
ID: |
1000005111659 |
Appl.
No.: |
16/690,185 |
Filed: |
November 21, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200165369 A1 |
May 28, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Nov 28, 2018 [JP] |
|
|
2018-222344 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F
222/20 (20130101); G02B 1/18 (20150115); C08F
2800/20 (20130101) |
Current International
Class: |
C08F
222/20 (20060101); G02B 1/18 (20150101) |
Field of
Search: |
;428/141 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2015-138150 |
|
Jul 2015 |
|
JP |
|
2018-059047 |
|
Apr 2018 |
|
JP |
|
2011/125970 |
|
Oct 2011 |
|
WO |
|
WO-2018012340 |
|
Jan 2018 |
|
WO |
|
2018/155317 |
|
Aug 2018 |
|
WO |
|
Primary Examiner: Khan; Tahseen
Attorney, Agent or Firm: Keating & Bennett, LLP
Claims
What is claimed is:
1. An antifouling film comprising: a substrate; and a polymer layer
disposed on a surface of the substrate and including on a surface
thereof an uneven structure provided with projections at a pitch
not longer than a wavelength of visible light, the polymer layer
being a cured product of a polymerizable composition, the
polymerizable composition containing, in terms of active
components, 75 to 95 wt % of a polymerizable monomer, 2.5 to 12.5
wt % of a urethane acrylate containing fluorine and an ester, and
2.5 to 9 wt % of a perfluoroalkyl-based monomer containing one
(meth)acryloyl group for each molecule, the polymerizable monomer
containing a bifunctional acrylate that contains an ethylene oxide
group and a multifunctional acrylate that contains no ethylene
oxide group, the perfluoroalkyl-based monomer having a fluorine
atom concentration of 50 to 60 wt %, the polymerizable composition
having an ethylene oxide group concentration of 20 to 50 wt %, the
polymerizable monomer further containing a monofunctional amide
monomer, and the polymerizable composition containing 1 to 15 wt %
of the monofunctional amide monomer, in terms of active
components.
2. The antifouling film according to claim 1, wherein the
multifunctional acrylate contains 3 to 6 functional groups.
3. The antifouling film according to claim 1, wherein the
polymerizable composition further contains a block copolymer
containing a fluorine segment and a non-fluorine segment.
4. The antifouling film according to claim 3, wherein the
polymerizable composition contains 0.1 to 5 wt % of the block
copolymer in terms of active components.
5. The antifouling film according to claim 1, wherein the
polymerizable composition further contains a photopolymerization
initiator, and the photopolymerization initiator contains an
acylphosphine oxide-based photopolymerization initiator and an
alkylphenone-based photopolymerization initiator.
6. The antifouling film according to claim 1, wherein the polymer
layer has a thickness of 5 to 20 .mu.m.
7. The antifouling film according to claim 1, wherein the
projections are disposed at an average pitch of 100 to 400 nm.
8. The antifouling film according to claim 1, wherein the
projections have an average height of 50 to 600 nm.
9. The antifouling film according to claim 1, wherein the
projections have an average aspect ratio of 0.8 to 1.5.
10. A polymerizable composition comprising in terms of active
components: 75 to 95 wt % of a polymerizable monomer; 2.5 to 12.5
wt % of a urethane acrylate containing fluorine and an ester; and
2.5 to 9 wt % of a perfluoroalkyl-based monomer containing one
(meth)acryloyl group for each molecule, the polymerizable monomer
containing a bifunctional acrylate that contains an ethylene oxide
group and a multifunctional acrylate that contains no ethylene
oxide group, the perfluoroalkyl-based monomer having a fluorine
atom concentration of 50 to 60 wt %, the polymerizable composition
having an ethylene oxide group concentration of 20 to 50 wt %, the
polymerizable monomer further containing a monofunctional amide
monomer, and the polymerizable composition containing 1 to 15 wt %
of the monofunctional amide monomer, in terms of active components.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. .sctn. 119
to Japanese Patent Application No. 2018-222344 filed on Nov. 28,
2018, the contents of which are incorporated herein by reference in
their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to antifouling films and
polymerizable compositions.
Description of Related Art
Various antireflective optical films have been studied (e.g., WO
2011/125970, JP 2018-59047, and WO 2018/155317). In particular,
optical films including an uneven structure of nanometer scale
(nanostructure) are known for their excellent antireflective
properties. This uneven structure has a continuously varying
refractive index from the air layer to the substrate, thereby
capable of reducing the reflected light significantly. Meanwhile,
hard coating films for an optical film, which have rubbing
resistance, have been studied (e.g., JP 2015-138150 A) although
they do not have antireflective properties.
BRIEF SUMMARY OF THE INVENTION
Although optical films including an uneven structure of nanometer
scale have excellent antireflective properties, the uneven
structure on the surface may cause easy spread of dirt such as
fingerprints (sebaceous dirt) sticking thereon and further cause
difficulty in wiping off such dirt present between projections.
Such sticking dirt has a reflectance that is very different from
the reflectance of the optical film, and thus is noticeable. This
has increased the demand for functional films (antifouling films)
including on their surfaces an uneven structure of nanometer scale
and showing excellent ease of wiping off dirt (e.g., ease of wiping
off fingerprints), i.e., excellent antifouling properties.
The present inventors made studies on such films, and found that
the antifouling properties thereof can be increased by using a
fluorine-based compound as a component of a polymer layer
constituting the uneven structure of the optical film.
Unfortunately, the inventors found through further studies that
some polymer layers having specific components have antifouling
properties that tend to decrease with time although they are high
at an initial stage. The optical films disclosed in WO 2011/125970,
JP 2018-59047, and WO 2018/155317 still have room for achieving
long-term high antifouling properties.
JP 2015-138150 A discloses a hard coat layer containing a
fluorine-based compound as a component. The disclosed technique,
unfortunately, is not applied to polymer layers having an uneven
structure as described above. Only using a fluorine-based compound
is not enough to impart long-term high antifouling properties to
polymer layers having an uneven structure.
In response to the above issues, an object of the present invention
is to provide an antifouling film having excellent rubbing
resistance and long-term high antifouling properties, and a
polymerizable composition for providing a polymer layer of the
antifouling film.
An aspect of the present invention may be an antifouling film
including: a substrate; and a polymer layer disposed on a surface
of the substrate and including on a surface thereof an uneven
structure provided with projections at a pitch not longer than a
wavelength of visible light, the polymer layer being a cured
product of a polymerizable composition, the polymerizable
composition containing, in terms of active components, 75 to 95 wt
% of a polymerizable monomer, 2.5 to 12.5 wt % of a urethane
acrylate containing fluorine and an ester, and 2.5 to 9 wt % of a
perfluoroalkyl-based monomer containing one (meth)acryloyl group
for each molecule, the polymerizable monomer containing a
bifunctional acrylate that contains an ethylene oxide group and a
multifunctional acrylate that contains no ethylene oxide group, the
perfluoroalkyl-based monomer having a fluorine atom concentration
of 50 to 60 wt %, the polymerizable composition having an ethylene
oxide group concentration of 20 to 50 wt %.
Another aspect of the present invention may be a polymerizable
composition including in terms of active components: 75 to 95 wt %
of a polymerizable monomer; 2.5 to 12.5 wt % of a urethane acrylate
containing fluorine and an ester; and 2.5 to 9 wt % of a
perfluoroalkyl-based monomer containing one (meth)acryloyl group
for each molecule, the polymerizable monomer containing a
bifunctional acrylate that contains an ethylene oxide group and a
multifunctional acrylate that contains no ethylene oxide group, the
perfluoroalkyl-based monomer having a fluorine atom concentration
of 50 to 60 wt %, the polymerizable composition having an ethylene
oxide group concentration of 20 to 50 wt %.
The present invention can provide an antifouling film having
excellent rubbing resistance and long-term high antifouling
properties and a polymerizable composition for providing a polymer
layer of the antifouling film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of an antifouling film
of an embodiment.
FIG. 2 is a schematic perspective view of a polymer layer in FIG.
1.
FIG. 3A is a schematic cross-sectional view illustrating an
exemplary method for producing the antifouling film of the
embodiment.
FIG. 3B is a schematic cross-sectional view illustrating the
exemplary method for producing the antifouling film of the
embodiment.
FIG. 3C is a schematic cross-sectional view illustrating the
exemplary method for producing the antifouling film of the
embodiment.
FIG. 3D is a schematic cross-sectional view illustrating the
exemplary method for producing the antifouling film of the
embodiment.
FIG. 3E is a schematic cross-sectional view illustrating the
exemplary method for producing the antifouling film of the
embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in more detail based on the
following embodiment with reference to the drawings. The
embodiment, however, is not intended to limit the scope of the
present invention. The configurations of the embodiment may
appropriately be combined or modified within the spirit of the
present invention.
The expression "X to Y" as used herein means "X or more and Y or
less".
Embodiment
An antifouling film of an embodiment is described below. FIG. 1 is
a schematic cross-sectional view of the antifouling film of the
embodiment. FIG. 2 is a schematic perspective view of a polymer
layer in FIG. 1.
An antifouling film 1 includes a substrate 2 and a polymer layer 3
disposed on a surface of the substrate 2.
<Substrate>
The material of the substrate 2 may be, for example, a resin such
as triacetyl cellulose (TAC), polyethylene terephthalate (PET), or
methyl methacrylate (MMA). The substrate 2 may further contain
appropriate additive(s) such as a plasticizer in addition to the
above material.
One surface (the surface close to the polymer layer 3) of the
substrate 2 may have undergone easy adhesion treatment (e.g.,
primer treatment). For example, a triacetyl cellulose film after
easy adhesion treatment may be used. The surface (the surface close
to the polymer layer 3) of the substrate 2 may alternatively have
undergone saponification treatment. For example, a saponified
triacetyl cellulose film may be used.
When the antifouling film 1 is mounted on a display device (e.g.,
liquid crystal display device) provided with a polarizing plate,
the substrate 2 may be part of the polarizing plate.
The substrate 2 preferably has a thickness of 50 to 100 .mu.m in
order to ensure the transparency and processability.
<Polymer Layer>
The polymer layer 3 includes on a surface thereof an uneven
structure provided with projections (protrusions) 4 at a pitch
(distance between the apexes of adjacent projections 4) P not
longer than the wavelength (780 nm) of visible light, i.e., a
moth-eye structure (a structure like a moth's eye). Thus, the
antifouling film 1 can exert excellent antireflective properties
(low reflectivity) owing to the moth-eye structure.
The thickness T of the polymer layer 3 is preferably small in order
to allow easy concentration of fluorine atoms in fluorine-based
compounds, which are to be added to the later described
polymerizable composition, on a surface (the surface remote from
the substrate 2) of the polymer layer 3. Specifically, the polymer
layer 3 has a thickness T of preferably 5 to 20 .mu.m, more
preferably 8 to 12 .mu.m.
Examples of the shape of each projection 4 include those tapering
toward the tip (tapered shapes) such as shapes consisting of a
columnar lower part and a hemispherical upper part
(temple-bell-like shapes) and conical shapes (cone-like shapes,
circular-cone-like shapes). In FIG. 1, the bases of the gaps
between any adjacent projections 4 are inclined, but the bases may
not be inclined but may be flat.
The projections 4 are disposed at an average pitch of preferably
100 to 400 nm, more preferably 100 to 200 nm, for sufficient
prevention of optical phenomena such as moire and iridescence. The
average pitch of the projections 4 specifically means the average
value of the pitches (P in FIG. 1) of all the adjacent projections
within a 1-.mu.m-square region in a plan image taken by a scanning
electron microscope.
The projections 4 have an average height of preferably 50 to 600
nm, more preferably 100 to 300 nm, for simultaneous achievement of
a preferred average height and a preferred average aspect ratio of
the projections 4, which is described later. The average height of
the projections 4 specifically means the average value of the
heights (H in FIG. 1) of 10 consecutive projections in a
cross-sectional image taken by a scanning electron microscope.
These 10 projections are selected so as not to include projections
having any defect or deformed portion (e.g., a portion accidentally
deformed during preparation of a measurement sample).
The projections 4 have an average aspect ratio of preferably 0.8 to
1.5, more preferably 1.0 to 1.3. If the average aspect ratio of the
projections 4 is smaller than 0.8, the film may insufficiently
prevent occurrence of optical phenomena such as moire and
iridescence, possibly failing to achieve excellent antireflective
properties. If the average aspect ratio of the projections 4 is
greater than 1.5, the processability of the uneven structure may be
poor, sticking may occur, and transfer conditions of a die in
formation of the uneven structure may be poor (clogging of the die
or twining of the material may occur). The average aspect ratio of
the projections 4 as used herein means the ratio of the average
height of the projections 4 to the average pitch of the projections
4 (height/pitch).
The projections 4 may be arranged either randomly or periodically
(regularly). Periodically arranged projections 4 may cause
unnecessary diffracted light due to the periodicity. Thus, the
projections 4 are preferably arranged randomly as shown in FIG.
2.
The polymer layer 3 is a cured product of a polymerizable
composition. Examples of the polymer layer 3 include a cured
product of an active energy ray-curable polymerizable composition
(cured product of a photopolymerizable composition) and a cured
product of a thermosetting polymerizable composition. The "active
energy rays" herein mean ultraviolet rays, visible light, infrared
rays, plasma, or the like. The polymer layer 3 is preferably a
cured product of an active energy ray-curable polymerizable
composition, more preferably a cured product of an ultraviolet
ray-curable polymerizable composition.
The polymerizable composition constituting the polymer layer 3
contains a polymerizable monomer (R), a urethane acrylate (S)
containing fluorine and an ester, and a perfluoroalkyl-based
monomer (T) containing one (meth)acryloyl group for each molecule.
The "(meth)acryloyl group" herein means an acryloyl group or a
methacryloyl group.
(Polymerizable Monomer (R))
The polymerizable monomer (R) is a monomer containing no fluorine
atoms and containing a polymerizable functional group (e.g.,
acryloyl group) that reacts with a different component by external
energy such as light or heat.
The polymerizable composition contains, in terms of active
components, 75 to 95 wt %, preferably 85 to 91 wt %, of the
polymerizable monomer (R). A polymerizable composition having a
polymerizable monomer (R) content of lower than 75 wt % in terms of
active components hardens the polymer layer 3 and reduces the
rubbing resistance of the antifouling film 1. A polymerizable
composition having a polymerizable monomer (R) content of higher
than 95 wt % in terms of active components fails to increase the
crosslinking density of the polymer layer 3 and reduces the rubbing
resistance of the antifouling film 1. When the surface (the surface
remote from the substrate 2) of the polymer layer 3 of such an
antifouling film 1 having reduced rubbing resistance is rubbed with
soft material such as non-woven cloth, for example, the projections
4 do not rise and the rubbed part has a reflectance different from
non-rubbed part and appears white. When the polymerizable
composition contains multiple kinds of the polymerizable monomers
(R), the total amount of the multiple kinds of the polymerizable
monomers (R) is 75 to 95 wt % in terms of active components.
The "active components" of the polymerizable composition herein
refer to those constituting the polymer layer after curing,
excluding those (e.g., solvent) not contributing to the curing
reaction (polymerization reaction).
The polymerizable monomer (R) contains a bifunctional acrylate (R1)
that contains an ethylene oxide group and a multifunctional
acrylate (R2) that contains no ethylene oxide group. The
"multifunctional acrylate" herein means an acrylate that contains
two or more acryloyl groups for each molecule. The "bifunctional
acrylate" thus means an acrylate that contains two acryloyl groups
for each molecule.
The presence of the multifunctional acrylate in the polymerizable
composition increases the crosslinking density of the polymer layer
3 and provides favorable elasticity (hardness), which increases the
rubbing resistance of the antifouling film 1. Studies by the
inventors have revealed that introducing an ethylene oxide group
(soft segment) into the multifunctional acrylate further increases
the rubbing resistance. Unfortunately, when the introduction of an
ethylene oxide group increases the molecular weight of the
multifunctional acrylate, the multifunctional acrylate may reduce
the compatibility of the polymerizable monomer (R) with other
component(s) (e.g., fluorine-based compound) in the polymerizable
composition, which may result in reduced transparency (whitening)
of the antifouling film 1 (polymer layer 3). In the present
embodiment, addition of the multifunctional acrylate (R2) ensures
the rubbing resistance to some extent, and addition of the
bifunctional acrylate (R1), which is prepared by introducing an
ethylene oxide group into a bifunctional acrylate having a
relatively low molecular weight, ensures the compatibility with
other component(s) (e.g., fluorine-based compound) in the
polymerizable composition and further increases the rubbing
resistance.
The polymerizable composition preferably contains 35 to 75 wt % of
the bifunctional acrylate (R1) in terms of active components. A
polymerizable composition having a bifunctional acrylate (R1)
content of lower than 35 wt % in terms of active components may
harden the polymer layer 3 and may reduce the rubbing resistance of
the antifouling film 1. A polymerizable composition having a
bifunctional acrylate (R1) content of higher than 75 wt % in terms
of active components may fail to increase the crosslinking density
of the polymer layer 3 and may reduce the rubbing resistance of the
antifouling film 1. When the polymerizable composition contains
multiple kinds of bifunctional acrylates (R1), the total amount of
the multiple kinds of bifunctional acrylates (R1) is preferably
within the above range in terms of active components.
Examples of the bifunctional acrylate (R1) include polyethylene
glycol (200) diacrylate and polyethylene glycol (400)
diacrylate.
Known examples of the polyethylene glycol (200) diacrylate include
"MIRAMER.RTM. M282" available from Miwon Specialty Chemical Co.,
Ltd. Known examples of the polyethylene glycol (400) diacrylate
include "MIRAMER M280" available from Miwon Specialty Chemical Co.,
Ltd.
The number of functional groups of the multifunctional acrylate
(R2) is 2 or more, preferably 3 to 6. "The number of functional
groups of a multifunctional acrylate" herein means the number of
acryloyl groups for each molecule. When the number of functional
groups of the multifunctional acrylate (R2) is more than 6, the
increase in the molecular weight reduces the compatibility with
other components (e.g., fluorine-based compound) in the
polymerizable composition, which may result in reduced transparency
(whitening) of the antifouling film 1 (polymer layer 3).
Furthermore, the polymer layer 3 may have too high a crosslinking
density and fluorine atoms in the fluorine-based compounds are less
likely to concentrate on the surface (the surface remote from the
substrate 2) of the polymer layer 3, which may fail to impart
long-term high antifouling properties to the antifouling film
1.
The polymerizable composition preferably contains 5 to 45 wt % of
the multifunctional acrylate (R2) in terms of active components. A
polymerizable composition having a multifunctional acrylate (R2)
content of lower than 5 wt % in terms of active components may
harden the polymer layer 3 and may reduce the rubbing resistance of
the antifouling film 1. A polymerizable composition having a
multifunctional acrylate (R2) content of higher than 45 wt % in
terms of active components may fail to increase the crosslinking
density of the polymer layer 3 and may reduce the rubbing
resistance of the antifouling film 1. When the polymerizable
composition contains multiple kinds of multifunctional acrylates
(R2), the total amount of the multiple kinds of multifunctional
acrylates (R2) is preferably within the above range in terms of
active components.
Examples of the multifunctional acrylate (R2) include
trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and
urethane acrylate.
Known examples of the trimethylolpropane triacrylate include
"MIRAMER M300" available from Miwon Specialty Chemical Co., Ltd.
Known examples of the dipentaerythritol hexaacrylate include
"MIRAMER M600" available from Miwon Specialty Chemical Co., Ltd.
Known examples of the urethane acrylate include "U-10HA" available
from Shin-Nakamura Chemical Co., Ltd.
The polymerizable monomer (R) may further contain a monofunctional
amide monomer. The "monofunctional amide monomer" herein means a
monomer that contains an amide group and contains one acryloyl
group for each molecule.
The presence of the monofunctional amide monomer in the
polymerizable composition increases the compatibility with a
fluorine-based compound, which allows easy concentration of
fluorine atoms in the fluorine-based compounds on the surface (the
surface remote from the substrate 2) of the polymer layer 3 and
sufficiently increases the antifouling properties of the
antifouling film 1. This also inhibits shrinkage during curing of
the polymerizable composition and increases the cohesion with the
substrate 2, whereby the adhesion between the polymer layer 3 and
the substrate 2 increases.
The polymerizable composition may contain preferably 1 to 15 wt %,
more preferably 5 to 10 wt %, of the monofunctional amide monomer
in terms of active components. A polymerizable composition having a
monofunctional amide monomer content of lower than 1 wt % in terms
of active components may fail to sufficiently increase the adhesion
between the polymer layer 3 and the substrate 2. A polymerizable
composition having a monofunctional amide monomer content of higher
than 15 wt % in terms of active components may cause permeation of
the monofunctional amide monomer into a die during die transferring
in formation of an uneven structure and may cause a reduction in
release properties of the die, whereby the antifouling film 1 may
fail to have sufficiently increased antifouling properties. A
polymerizable composition having such a monofunctional amide
monomer content may also fail to increase the crosslinking density
of the polymer layer 3 and reduce the rubbing resistance of the
antifouling film 1. When the polymerizable composition contains
multiple kinds of monofunctional amide monomers, the total amount
of the multiple kinds of monofunctional amide monomers is
preferably within the above range in terms of active
components.
Examples of the monofunctional amide monomer include
N-acryloylmorpholine, N,N-dimethylacrylamide,
N,N-diethylacrylamide, N-(2-hydroxyethyl)acrylamide, diacetone
acrylamide, and N-n-butoxymethylacrylamide.
Known examples of the N-acryloylmorpholine include "ACMO.RTM." from
KJ Chemicals Corp. Known examples of the N,N-dimethylacrylamide
include "DMAA.RTM." from KJ Chemicals Corp. Known examples of the
N,N-diethylacrylamide include "DEAA.RTM." from KJ Chemicals Corp.
Known examples of the N-(2-hydroxyethyl)acrylamide include
"HEAA.RTM." from KJ Chemicals Corp. Known examples of the diacetone
acrylamide include "DAAM.RTM." from Nippon Kasei Chemical Co., Ltd.
Known examples of the N-n-butoxymethylacrylamide include "NBMA"
from MRC Unitec Co., Ltd.
(Urethane Acrylate (S))
The urethane acrylate (S) is a urethane acrylate containing a
fluorine atom and an ester bond, that is, one of fluorine-based
compounds. The ester bond in the urethane acrylate (S) is an ester
bond derived from an isocyanate component containing an acryloyloxy
group or an ester bond derived from an acrylate component
containing an active hydrogen atom. The acryloyl group in the
urethane acrylate (S) functions as a polymerizable functional group
that reacts with a different component by external energy such as
light or heat.
The presence of the urethane acrylate (S) in the polymerizable
composition allows concentration of fluorine atoms derived from the
urethane acrylate (S) on the surface (the surface remote from the
substrate 2) of the polymer layer 3 and reduces the surface free
energy of the polymer layer 3, which increases the antifouling
properties of the antifouling film 1. The urethane acrylate (S) has
a low molecular weight and low affinity with an ethylene oxide
group, and thus tends to move to the surface (the surface remote
from the substrate 2) of the polymer layer 3. Accordingly, the
antifouling properties of the antifouling film 1 tend to be
increased even with a small amount of the urethane acrylate (S). In
addition, the acryloyl groups in the urethane acrylate (S)
crosslink in the polymer layer 3, which imparts long-term high
antifouling properties to the antifouling film 1. Furthermore, the
urethane acrylate (S), containing a strong ester bond, tends to
increase the rubbing resistance of the antifouling film 1.
The urethane acrylate (S) has a weight average molecular weight
determined by gel permeation chromatography (GPC) and calibrated
with polystyrene standards of preferably 100 to 100000, more
preferably 200 to 20000, still more preferably 300 to 2000. A
urethane acrylate (S) having a weight average molecular weight of
lower than 100 may penetrate the polymer layer 3 by the flip-flop
effect, which may fail to impart long-term high antifouling
properties to the antifouling film 1. A urethane acrylate (S)
having a weight average molecular weight of higher than 100000 is
less likely to concentrate on the surface (the surface remote from
the substrate 2) of the polymer layer 3, which may fail to impart
long-term high antifouling properties to the antifouling film
1.
The polymerizable composition contains 2.5 to 12.5 wt %, preferably
3.5 to 10 wt %, of the urethane acrylate (S) in terms of active
components. A polymerizable composition having a urethane acrylate
(S) content of lower than 2.5 wt % in terms of active components
reduces the number of fluorine atoms that concentrate on the
surface (the surface remote from the substrate 2) of the polymer
layer 3, reducing the antifouling properties of the antifouling
film 1. A polymerizable composition having a urethane acrylate (S)
content of higher than 12.5 wt % in terms of active components
reduces the compatibility of the urethane acrylate (S) with other
component(s) in the polymerizable composition, which results in
reduced transparency (whitening) of the antifouling film 1 (polymer
layer 3). When the polymerizable composition contains multiple
kinds of urethane acrylates (S), the total amount of multiple kinds
of urethane acrylates (S) is 2.5 to 12.5 wt % in terms of active
components.
Known examples of the urethane acrylate (S) include "EBECRYL.RTM.
8110" available from Daicel-Allnex Ltd. and "Megaface.RTM. RS-75"
available from DIC Corporation, as disclosed in JP 2015-138150 A.
Each of these fluorine-based compounds is one of
perfluoroalkyl-based oligomers. The "perfluoroalkyl-based oligomer"
herein means a fluorine-based oligomer containing a perfluoroalkyl
group.
Differently from the present embodiment, if the polymerizable
composition contains not the urethane acrylate (S) but a
fluorine-containing polyether-based urethane acrylate, for example,
the resulting antifouling film 1 fails to have long-term high
antifouling properties. Known examples of the fluorine-containing
polyether-based urethane acrylate include "Ftergent.RTM. 602A"
available from Neos Co., Ltd. as disclosed in JP 2015-138150 A.
Similarly to the known examples of the urethane acrylate (S), this
fluorine-based compound is also one of perfluoroalkyl-based
oligomers, but is inferior to the known examples in imparting
long-term high antifouling properties to the antifouling film
1.
(Perfluoroalkyl-Based Monomer (T))
The perfluoroalkyl-based monomer (T) is a perfluoroalkyl-based
monomer containing one (meth)acryloyl group for each molecule, that
is, one of fluorine-based compounds. The "perfluoroalkyl-based
monomer" herein means a fluorine-based monomer containing a
perfluoroalkyl group. The (meth)acryloyl group in the
perfluoroalkyl-based monomer (T) functions as a polymerizable
functional group that reacts with a different component(s) by
external energy such as light or heat.
The presence of the perfluoroalkyl-based monomer (T) in the
polymerizable composition allows concentration of fluorine atoms
derived from the perfluoroalkyl-based monomer (T) on the surface
(the surface remote from the substrate 2) of the polymer layer 3
and reduces the surface free energy of the polymer layer 3, which
increases the antifouling properties of the antifouling film 1. The
perfluoroalkyl-based monomer (T) has a low molecular weight, and
thus tends to move to the surface (the surface remote from the
substrate 2) of the polymer layer 3. Accordingly, the antifouling
properties of the antifouling film 1 tend to be increased even with
a small amount of the perfluoroalkyl-based monomer (T). In
addition, the acryloyl groups in the perfluoroalkyl-based monomer
(T) crosslink in the polymerizable composition, which imparts
long-term high antifouling properties to the antifouling film
1.
If the polymerizable composition contains not the
perfluoroalkyl-based monomer (T) but a perfluoroalkyl-based monomer
containing two or more (meth)acryloyl groups for each molecule, the
high molecular weight of the perfluoroalkyl-based monomer
containing two or more (meth)acryloyl groups for each molecule
reduces the compatibility with other component(s) in the
polymerizable composition, which results in reduced transparency
(whitening) of the antifouling film 1 (polymer layer 3).
Furthermore, the perfluoroalkyl-based monomer containing two or
more (meth)acryloyl groups for each molecule, which forms a main
skeleton or a branch in the polymer layer 3 and tends to be taken
into a crosslink structure, is less likely to concentrate on the
surface (the surface remote from the substrate 2) of the polymer
layer 3 than the perfluoroalkyl-based monomer (T).
The perfluoroalkyl-based monomer (T) has a fluorine atom
concentration of 50 to 60 wt %, preferably 52 to 60 wt %. A
perfluoroalkyl-based monomer (T) having a fluorine atom
concentration of lower than 50 wt % reduces the number of fluorine
atoms that concentrate on the surface (the surface remote from the
substrate 2) of the polymer layer 3, reducing the antifouling
properties of the antifouling film 1. A perfluoroalkyl-based
monomer (T) having a fluorine atom concentration of higher than 60
wt % softens the polymer layer 3 and thereby reduces the rubbing
resistance, and also has reduced compatibility of the
perfluoroalkyl-based monomer (T) with other component(s) in the
polymerizable composition and thereby causes reduced transparency
(whitening) of the antifouling film 1 (polymer layer 3).
The polymerizable composition contains 2.5 to 9 wt %, preferably 3
to 7 wt %, of the perfluoroalkyl-based monomer (T) in terms of
active components. A polymerizable composition having a
perfluoroalkyl-based monomer (T) content of lower than 2.5 wt % in
terms of active components reduces the number of fluorine atoms
that concentrate on the surface (the surface remote from the
substrate 2) of the polymer layer 3, reducing the antifouling
properties of the antifouling film 1. A polymerizable composition
having a perfluoroalkyl-based monomer (T) content of higher than 9
wt % in terms of active components reduces the compatibility with
other component(s) in the polymerizable composition, which results
in reduced transparency (whitening) of the antifouling film 1
(polymer layer 3). When the polymerizable composition contains
multiple kinds of perfluoroalkyl-based monomers (T), the total
amount of multiple kinds of perfluoroalkyl-based monomers (T) is
2.5 to 9 wt % in terms of active components.
Examples of the perfluoroalkyl-based monomer (T) include
2-(perfluorohexyl)ethyl acrylate, 2-(perfluorobutyl) ethyl
acrylate, 2-(perfluorohexyl)ethyl methacrylate,
2-(perfluorobutyl)ethyl methacrylate, 1H,1H,5H-octafluoropentyl
acrylate, and 1H,1H,5H-octafluoropentyl methacrylate.
Known examples of the 2-(perfluorohexyl)ethyl acrylate include
"CHEMINOX.RTM. FAAC-6" available from Unimatec Corporation. Known
examples of the 2-(perfluorobutyl)ethyl acrylate include "CHEMINOX
FAAC-4" available from Unimatec Corporation. Known examples of the
2-(perfluorohexyl)ethyl methacrylate include "CHEMINOX FAMAC-6"
available from Unimatec Corporation. Known examples of the
2-(perfluorobutyl)ethyl methacrylate include "CHEMINOX FAMAC-4"
available from Unimatec Corporation. Known examples of the
1H,1H,5H-octafluoropentyl acrylate include "Viscoat 8F" available
from Osaka Organic Chemical Industry Ltd. Known examples of the
1H,1H,5H-octafluoropentyl methacrylate include "Viscoat 8FM"
available from Osaka Organic Chemical Industry Ltd.
The polymerizable composition has an ethylene oxide group
concentration of 20 to 50 wt %, preferably 25 to 45 wt %, more
preferably 30 to 40 wt %. A polymerizable composition having an
ethylene oxide group concentration of lower than 20 wt % increases
the crosslinking density of the polymer layer 3 and reduces the
polarity of the polymer layer 3, which inhibits concentration of
fluorine atoms in the fluorine-based compounds on the surface (the
surface remote from the substrate 2) of the polymer layer 3 and
fails to impart long-term high antifouling properties to the
antifouling film 1. A polymerizable composition having an ethylene
oxide group concentration of higher than 50 wt % reduces the
solubility of the fluorine-based compounds in the polymerizable
composition, which results in reduced transparency (whitening) of
the antifouling film 1 (polymer layer 3).
In the present embodiment, the polymerizable composition
constituting the polymer layer 3 contains the urethane acrylate (S)
and the perfluoroalkyl-based monomer (T) as fluorine-based
compounds and has an ethylene oxide group concentration within the
predetermined range. Therefore, more fluorine atoms concentrate on
the surface (the surface remote from the substrate 2) of the
polymer layer 3, which tends to impart long-term high antifouling
properties to the antifouling film 1.
The polymerizable composition contains at least the urethane
acrylate (S) and the perfluoroalkyl-based monomer (T) as
fluorine-based compounds, and may further contain a
perfluoropolyether-based oligomer. The "perfluoropolyether-based
oligomer" herein means a fluorine-based oligomer containing a
perfluoropolyether group.
Known examples of the perfluoropolyether-based oligomer include
"Fomblin.RTM. MT70" available from Solvay Japan, Ltd. and
"X-27-1203E" available from Shin-Etsu Chemical Co., Ltd.
Differently from the present embodiment, if the polymerizable
composition contains not the urethane acrylate (S) but a
perfluoropolyether-based oligomer, for example, the resulting
antifouling film 1 fails to have long-term high antifouling
properties. The perfluoropolyether-based oligomer, containing a
perfluoropolyether group, has high affinity with hexadecane and
artificial contamination liquids, which are often used as assumed
contaminants in evaluation for antifouling properties. Thus, if a
large amount of the perfluoropolyether-based oligomer concentrates
on the surface (the surface remote from the substrate 2) of the
polymer layer 3, hexadecane or an artificial contamination liquid
stuck on the surface significantly spread in a wet state with time.
In other words, the antifouling film 1 fails to have long-term high
antifouling properties.
The polymerizable composition may further contain a block copolymer
containing a fluorine segment and a non-fluorine segment. The
"fluorine segment" herein means a cured product (polymer) of a
monomer mainly containing a fluorine-based monomer. The
fluorine-based monomer may be any radically polymerizable monomer
containing a fluorine atom. The "non-fluorine segment" herein means
a cured product (polymer) of a monomer mainly containing a
non-fluorine-based monomer. The non-fluorine-based monomer may be
any radically polymerizable monomer containing no fluorine
atom.
The presence of the block copolymer in the polymerizable
composition allows the non-fluorine segment to function as a
compatible segment having compatibility with other component(s) in
the polymerizable composition and allows concentration of the
fluorine segment (fluorine atoms derived from the fluorine segment)
on the surface (the surface remote from the substrate 2) of the
polymer layer 3. This reduces the surface free energy of the
polymer layer 3 and sufficiently increases the antifouling
properties of the antifouling film 1. The block copolymer tends to
be fixed in the polymer layer 3 by the compatible-segment function
of the non-fluorine segment, which tends to impart long-term high
antifouling properties to the antifouling film 1.
The block copolymer contains preferably 10 to 90 wt %, more
preferably 35 to 65 wt %, of the fluorine segment. A block
copolymer containing lower than 10 wt % of the fluorine segment may
fail to achieve sufficient properties as the fluorine segment,
i.e., sufficient antifouling properties. A block copolymer
containing higher than 90 wt % of the fluorine segment may reduce
the compatibility with other component(s) in the polymerizable
composition, which may result in reduced transparency (whitening)
of the antifouling film 1 (polymer layer 3).
The block copolymer has a number average molecular weight of
preferably 5000 to 1000000, more preferably 10000 to 300000, still
more preferably 10000 to 100000. A block copolymer having a number
average molecular weight of lower than 5000 may provide a short
fluorine segment and may fail to impart sufficient properties,
i.e., sufficient antifouling properties of the fluorine segment. A
block copolymer having a number average molecular weight of higher
than 1000000 may reduce the compatibility of the block copolymer
with other component(s) in the polymerizable composition, which may
result in reduced transparency (whitening) of the antifouling film
1 (polymer layer 3).
The block copolymer is preferably a perfluoroalkyl-based copolymer.
The "perfluoroalkyl-based copolymer" herein means a fluorine-based
copolymer containing a perfluoroalkyl group. When the block
copolymer is a perfluoroalkyl-based copolymer, the fluorine segment
tends to concentrate on the surface (the surface remote from the
substrate 2) of the polymer layer 3 (rigid molecular chains tend to
align in a rising state). Thus, fluorine atoms tend to be densely
distributed on the surface (the surface remote from the substrate
2) of the polymer layer 3, which tends to increase the antifouling
properties of the antifouling film 1.
The block copolymer may not contain a (meth)acryloyl group
functioning as a polymerizable functional group. Since the block
copolymer contains the non-fluorine segment having compatibility
with other component(s) in the polymerizable composition, even a
block copolymer containing no (meth)acryloyl group as a
polymerizable functional group tends to be fixed in the polymer
layer 3.
The polymerizable composition contains 0.1 to 5 wt %, preferably
0.5 to 3 wt %, of the block copolymer in terms of active
components. A polymerizable composition having a block copolymer
content of lower than 0.1 wt % in terms of active components may
reduce the number of fluorine atoms that concentrate on the surface
(the surface remote from the substrate 2) of the polymer layer 3
and may fail to sufficiently increase the antifouling properties of
the antifouling film 1. A polymerizable composition having a block
copolymer content of higher than 5 wt % in terms of active
components may reduce the compatibility with other component(s) in
the polymerizable composition, which may result in reduced
transparency (whitening) of the antifouling film 1 (polymer layer
3). When the polymerizable composition contains multiple kinds of
block copolymers, the total amount of the multiple kinds of block
copolymers is preferably within the above range in terms of active
components.
Known examples of the block copolymer include "Modiper.RTM. F606",
"Modiper F206", and "Modiper F3636", all available from NOF
Corporation.
The polymerizable composition may further contain a polymerization
initiator. Use of the polymerization initiator in the polymerizable
composition increases the curability of the polymerizable
composition.
Examples of the polymerization initiator include
photopolymerization initiators and thermal polymerization
initiators, with the photopolymerization initiators preferred. The
photopolymerization initiators are active to active energy
rays.
The polymerizable composition preferably contains 1 to 3 wt % of
the photopolymerization initiator in terms of active components.
When the polymerizable composition contains multiple kinds of
photopolymerization initiators, the total amount of the multiple
kinds of photopolymerization initiators is preferably within the
above range in terms of active components.
Examples of the photopolymerization initiator include radical
polymerization initiators, anionic polymerization initiators, and
cationic polymerization initiators. Examples of such a
photopolymerization initiator include acetophenone-based
photopolymerization initiators such as
p-tert-butyltrichloroacetophenone, 2,2'-diethoxyacetophenone, and
2-hydroxy-2-methyl-1-phenylpropan-1-one; ketone-based
photopolymerization initiators such as benzophenone,
4,4'-bisdimethylaminobenzophenone, 2-chlorothioxanthone,
2-methylthioxanthone, 2-ethylthioxanthone, and
2-isopropylthioxanthone; benzoin ether-based photopolymerization
initiators such as benzoin, benzoin methyl ether, benzoin isopropyl
ether, and benzoin isobutyl ether; benzyl ketal-based
photopolymerization initiators such as benzyl dimethyl ketal and
hydroxycyclohexyl phenyl ketone; acylphosphine oxide-based
photopolymerization initiators such as
bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide and
diphenyl(2,4,6-trimethoxybenzoyl)phosphine oxide; and
alkylphenone-based photopolymerization initiators such as
1-hydroxy-cyclohexyl-phenyl-ketone.
The photopolymerization initiator preferably contains an
acylphosphine oxide-based photopolymerization initiator and an
alkylphenone-based photopolymerization initiator. Use of both the
acylphosphine oxide-based photopolymerization initiator and the
alkylphenone-based photopolymerization initiator as the
photopolymerization initiators significantly increases the
curability of the polymerizable composition and promotes curing
(significantly reduces uncured part) of the entire polymer layer 3
(including the surface close to the substrate 2 and the surface
remote from the substrate 2), which resultantly allows easy
concentration of fluorine atoms in the fluorine-based compounds on
the surface (the surface remote from the substrate 2) of the
polymer layer 3.
The polymerizable composition preferably contains 0.5 to 1.5 wt %
of the acylphosphine oxide-based photopolymerization initiator in
terms of active components. When the polymerizable composition
contains multiple kinds of acylphosphine oxide-based
photopolymerization initiators, the total amount of the multiple
kinds of acylphosphine oxide-based photopolymerization initiators
is preferably within the above range in terms of active
components.
Concerning the acylphosphine oxide-based photopolymerization
initiator, known examples of the
bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide include
"Omnirad.RTM. 819" available from IGM Resins B.V. Known examples of
the diphenyl(2,4,6-trimethoxybenzoyl)phosphine oxide include
"Omnirad TPO" available from IGM Resins B.V.
The polymerizable composition preferably contains 0.5 to 1.5 wt %
of the alkylphenone-based photopolymerization initiator in terms of
active components. When the polymerizable composition contains
multiple kinds of alkylphenone-based photopolymerization
initiators, the total amount of the multiple kinds of
alkylphenone-based photopolymerization initiators is preferably
within the above range in terms of active components.
Concerning the alkylphenone-based photopolymerization initiator,
known examples of the 1-hydroxy-cyclohexyl-phenyl-ketone include
"Omnirad 184" available from IGM Resins B.V.
The polymerizable composition may further contain a solvent. In
this case, the solvent may be present together with active
components in any of the components, or may be present separately
from the components.
Examples of the solvent include alcohols (C1-C10 alcohols such as
methanol, ethanol, n- or i-propanol, n-, sec-, or t-butanol, benzyl
alcohol, and octanol), ketones (C3-C8 ketones such as acetone,
methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone,
dibutyl ketone, and cyclohexanone), esters or ether esters (C4-C10
esters such as ethyl acetate, butyl acetate, and ethyl lactate),
.gamma.-butyrolactone, ethylene glycol monomethyl acetate,
propylene glycol monomethyl acetate, ethers (C4-C10 ethers such as
EG monomethyl ether (methyl cellosolve), EG monomethyl ether (ethyl
cellosolve), diethylene glycol monobutyl ether (butyl cellosolve),
and propylene glycol monomethyl ether), aromatic hydrocarbons
(C6-C10 aromatic hydrocarbons such as benzene, toluene, and
xylene), amides (C3-C10 amides such as dimethylformamide,
dimethylacetamide, and N-methylpyrrolidone), halogenated
hydrocarbons (C1-C2 halogenated hydrocarbons such as methylene
dichloride and ethylene dichloride), and petroleum-based solvents
(e.g., petroleum ether, petroleum naphtha).
In terms of the antifouling properties, the polymer layer 3
preferably has a surface (surface remote from the substrate 2) that
shows a contact angle with hexadecane of 30.degree. or greater,
more preferably 70.degree. or greater, still more preferably
90.degree. or greater.
The antifouling film 1 may be used in any way that utilizes the
excellent antifouling properties, and may be used as, for example,
an optical film such as an antireflective film. Such an
antireflective film contributes to an increase in visibility when
it is mounted inside or outside a display device.
The antifouling properties of the antifouling film 1 may mean that
dirt adhering to the surface (the surface remote from the substrate
2) of the polymer layer 3 is easily removable, or that dirt is not
likely to adhere to the surface (the surface remote from the
substrate 2) of the polymer layer 3. The antifouling film 1, owing
to the lotus effect provided by its moth-eye structure, can achieve
better antifouling properties than a conventional antifouling film
(e.g., fluorine-containing film) having a normal surface such as a
flat surface.
The antifouling film 1 may be produced by the following production
method, for example. FIG. 3A, FIG. 3B, FIG. 3C, FIG. 3D, and FIG.
3E are schematic cross-sectional views illustrating an exemplary
method for producing the antifouling film of the embodiment.
(A) Release Treatment of Die
As shown in FIG. 3A, a release agent 7 is applied to the surface of
a die 5.
Examples of techniques of applying the release agent 7 include
spray coating, gravure coating, slot-die coating, bar coating, and
potting.
(B) Application of Polymerizable Composition
As shown in FIG. 3B, a polymerizable composition 6 is applied to a
surface of the substrate 2.
Examples of techniques of applying the polymerizable composition 6
include spray coating, gravure coating, slot-die coating, and bar
coating. Among these, gravure coating or slot-die coating is
preferred in order to level the thickness of the resulting film and
to achieve good productivity.
The polymerizable composition 6 contains, in terms of active
components, 75 to 95 wt % of the polymerizable monomer (R), 2.5 to
12.5 wt % of the urethane acrylate (S), and 2.5 to 9 wt % of the
perfluoroalkyl-based monomer (T), and has an ethylene oxide group
concentration of 20 to 50 wt %. When the polymerizable composition
6 further contains a solvent, heating (drying) may be performed to
remove the solvent after application of the polymerizable
composition 6. The heating is preferably performed at a temperature
equal to or higher than the boiling point of the solvent.
The above processes (A) and (B) may be performed at the same timing
or at different timings.
(C) Formation of Uneven Structure
The substrate 2 is pushed to the surface coated with the release
agent 7 of the die 5 with the polymerizable composition 6 in
between. As a result, an uneven structure is formed on the surface
(the surface remote from the substrate 2) of the polymerizable
composition 6 as shown in FIG. 3C.
(D) Formation of Polymer Layer
The polymerizable composition 6 is cured. As a result, the polymer
layer 3 is formed as shown in FIG. 3D.
Curing of the polymerizable composition 6 is achieved by, for
example, application of active energy rays or heating. The
polymerizable composition 6 is cured preferably by application of
active energy rays, more preferably by application of ultraviolet
rays. Application of active energy rays may be performed from the
substrate 2 side of the polymerizable composition 6, or may be
performed from the die 5 side of the polymerizable composition 6.
Application of active energy rays to the polymerizable composition
6 may be performed once or multiple times.
The above processes (C) and (D) may be performed at the same timing
or at different timings.
(E) Die Removal
As shown in FIG. 3E, the die 5 is removed from the polymer layer
3.
After the die 5 is removed from the polymer layer 3, the polymer
layer 3 may be irradiated with active energy rays (e.g.,
ultraviolet rays) from the side remote from the substrate 2.
Irradiation with active energy rays after the removal of the die 5
as well as before the removal of the die 5 (in the process (D))
promotes curing (significantly reduces uncured part) of the entire
polymer layer 3 (including the surface close to the substrate 2 and
the surface remote from the substrate 2), which resultantly allows
easy concentration of fluorine atoms in the fluorine-based
compounds on the surface (the surface remote from the substrate 2)
of the polymer layer 3.
A specific case for easily achieving such effects is described
below in which the polymerizable composition 6 contains an
acylphosphine oxide-based photopolymerization initiator and an
alkylphenone-based photopolymerization initiator and the substrate
2 is a triacetyl cellulose film.
First, when the polymerizable composition 6 is irradiated with
ultraviolet rays from the substrate 2 side before the removal of
the die 5 (in the process (D)), the acylphosphine oxide-based
photopolymerization initiator more promotes curing reaction of the
polymerizable composition 6 on the substrate 2 side. This is due to
the following reasons 1 and 2.
(Reason 1) An acylphosphine oxide-based photopolymerization
initiator absorbs ultraviolet rays within a wavelength range (e.g.,
about 450 nm or shorter for "Omnirad 819" available from IGM Resins
B.V.) that is wider than and encompasses the wavelength range
(about 380 nm or shorter) of ultraviolet rays absorbed by a
triacetyl cellulose film. In other words, ultraviolet rays having
passed through a triacetyl cellulose film without being absorbed
can be absorbed by an acylphosphine oxide-based photopolymerization
initiator.
(Reason 2) An alkylphenone-based photopolymerization initiator
absorbs ultraviolet rays within a wavelength range (e.g., about 380
nm or shorter for "Omnirad 184" available from IGM Resins B.V.)
that is encompassed by the wavelength range of ultraviolet rays
absorbed by a triacetyl cellulose film (about 380 nm or shorter).
In other words, ultraviolet rays having passed through a triacetyl
cellulose film without being absorbed is not absorbed by an
alkylphenone-based photopolymerization initiator.
Next, when the polymer layer 3 is irradiated with ultraviolet rays
from the side remote from the substrate 2 after the removal of the
die 5 (in the process (E)), the alkylphenone-based
photopolymerization initiator more promotes curing reaction of
uncured part in the polymer layer 3 on the side remote from the
substrate 2.
As described, irradiation of active energy rays before and after
the removal of the die 5 (in the processes (D) and (E)) promotes
curing (significantly reduces uncured part) of the entire polymer
layer 3 (including the surface close to the substrate 2 and the
surface remote from the substrate 2), which resultantly allows easy
concentration of fluorine atoms in the fluorine-based compounds on
the surface (the surface remote from the substrate 2) of the
polymer layer 3.
The above processes (A) to (E) complete the antifouling film 1. A
series of processes such as a series of the processes (B) to (E)
herein is also referred to as "die transferring". In the present
production example, when the antifouling film 1 is continuously
produced, the process (A) may be performed at least once at an
initial stage (before first transferring), and then the processes
(B) to (E) may be repeated. Specifically, the process (A) may be
skipped at the second or after transferring: for example, the
processes may be performed in the order of (A), (B), (C), (D), (E),
(B), (C), (D), (E), (B), (C), (D), (E), and the like. The process
(A) may be performed again appropriately at the second or after
transferring: for example, the processes may be performed in the
order of (A), (B), (C), (D), (E), (B), (C), (D), (E), (A), (B),
(C), (D), (E), and the like (in this case, the process (A) is
performed again at the third transferring). In such die
transferring, the substrate 2 in the form of a roll, for example,
enables continuous and efficient performing of the processes (B) to
(E).
<Die>
The die 5 may be one produced by the following method. First, a
film of aluminum as a material of the die 5 is formed on a surface
of a support by sputtering. Next, the resulting aluminum layer is
repetitively subjected to anodizing and etching. Thereby, a cavity
(die 5) of the moth-eye structure can be produced. At this time,
the uneven structure of the die 5 can be modified by adjusting the
duration of the anodizing and the duration of the etching.
Examples of the material of the support include glass; metals such
as stainless steel and nickel; polyolefinic resins such as
polypropylene, polymethylpentene, and cyclic olefinic polymers
(typified by norbornene-based resin, e.g., "Zeonor.RTM." from Zeon
Corp., "Arton.RTM." from JSR Corp.); polycarbonate resin; and
resins such as polyethylene terephthalate, polyethylene
naphthalate, and triacetyl cellulose. Instead of the support with
an aluminum film formed on the surface, an aluminum support may be
used.
The die 5 may be in the form of a flat plate or a roll, for
example.
<Release Agent>
The release agent 7 is used for release treatment on the surface of
the die 5. The release agent 7 increases the release properties
(e.g., water repellency) of the die 5. Thus, the die 5 can be
easily removed from the polymer layer 3. Further, this treatment
makes the surface free energy of the die 5 low, and thus fluorine
atoms in the fluorine-based compounds added to the polymerizable
composition 6 can uniformly be distributed on the surface (the
surface remote from the substrate 2) of the polymerizable
composition 6 when the substrate 2 is pushed to the die 5. Further,
this treatment can prevent early removal of the fluorine atoms from
the surface (the surface remote from the substrate 2) of the
polymerizable composition 6 before curing of the polymerizable
composition 6. As a result, in the antifouling film 1, the fluorine
atoms can uniformly be distributed on the surface (the surface
remote from the substrate 2) of the polymer layer 3.
Examples of the release agent 7 include fluorine-based release
agents, silicone-based release agents, and phosphate-ester-based
release agents, with the fluorine-based release agents preferred.
Preferred among the fluorine-based release agents are
perfluoropolyether-based release agents. Known examples thereof
include "Optool.RTM. DSX", "Optool UD509", and "Optool AES4" from
Daikin Industries, Ltd.
EXAMPLES AND COMPARATIVE EXAMPLES
The present invention is described in more detail based on the
following examples and comparative examples. The examples, however,
are not intended to limit the scope of the present invention.
The materials used in production of the antifouling films in the
examples and comparative examples were as follows.
<Substrate>
"TAC-TD80U" from Fujifilm Corp. was used. The thickness thereof was
80 .mu.m.
<Die>
A die produced by the following method was used. First, a film of
aluminum as a material of the die was formed on a 10-cm-square
glass substrate by sputtering. The thickness of the resulting
aluminum layer was 1.0 .mu.m. Next, the resulting aluminum layer
was repetitively subjected to anodizing and etching. Thereby, an
anodized layer was formed with many fine pores (distance between
the bottom points of adjacent pores (recesses) was not longer than
the wavelength of visible light). Specifically, anodizing, etching,
anodizing, etching, anodizing, etching, anodizing, etching, and
anodizing were performed in the stated order (anodizing: 5 times,
etching: 4 times), so that many fine pores (recesses) were formed
each tapering toward the inside of the aluminum layer (a tapered
shape). As a result, a die having an uneven structure was obtained.
The anodizing was performed using oxalic acid (concentration: 0.03
wt %) at a liquid temperature of 5.degree. C. and an applied
voltage of 80 V. The duration of a single anodizing process was 25
seconds. The etching was performed using phosphoric acid
(concentration: 1 mol/l) at a liquid temperature of 30.degree. C.
The duration of a single etching process was 25 minutes. The die
was found to have a recess depth of 290 nm by scanning electron
microscopic observation.
<Release Agent>
"Optool UD509" from Daikin Industries, Ltd. was used. The active
component concentration thereof was 0.001 wt %.
<Polymerizable Composition>
Polymerizable compositions A1 to A18 and B1 to B16 having the
respective compositions (amounts of active components) shown in
Tables 1 to 8 were used. The abbreviations of the respective
components are as follows.
(Bifunctional Acrylate (R1))
"M282"
"MIRAMER M282" available from Miwon Specialty Chemical Co.,
Ltd.
Active component concentration: 100 wt %
Number of functional groups: 2
Number of ethylene oxide groups: 4 for each molecule
"M280"
"MIRAMER M280" available from Miwon Specialty Chemical Co.,
Ltd.
Active component concentration: 100 wt %
Number of functional groups: 2
Number of ethylene oxide groups: 9 for each molecule
(Multifunctional Acrylate (R2))
"M300"
"MIRAMER M300" available from Miwon Specialty Chemical Co.,
Ltd.
Active component concentration: 100 wt %
Number of functional groups: 3
Number of ethylene oxide groups: 0 for each molecule
"M600"
"MIRAMER M600" available from Miwon Specialty Chemical Co.,
Ltd.
Active component concentration: 100 wt %
Number of functional groups: 6
Number of ethylene oxide groups: 0 for each molecule
"U-10"
"U-10HA" available from Shin-Nakamura Chemical Co., Ltd.
Active component concentration: 100 wt %
Number of functional groups: 10
Number of ethylene oxide groups: 0 for each molecule
(Multifunctional Acrylate Other than Bifunctional Acrylate (R1) and
Multifunctional Acrylate (R2))
"5027E"
"NK Economer.RTM. A-PG5027E" available from Shin-Nakamura Chemical
Co., Ltd.
Active component concentration: 100 wt %
Number of functional groups: 9
Number of ethylene oxide groups: 27 for each molecule
(Monofunctional Amide Monomer)
"AC"
"ACMO" available from KJ Chemicals Corporation
Active component concentration: 100 wt %
(Reactive Diluent)
"E8110R"
Reactive diluent (active components) derived from "EBECRYL 8110"
available from Daicel-Allnex Ltd.
Concentration in "EBECRYL 8110": about 50 wt %
(Urethane Acrylate (S))
"E8110"
Fluorine-based compound (active components) derived from "EBECRYL
8110" available from Daicel-Allnex Ltd.
Concentration in "EBECRYL 8110": about 50 wt %
"RS-75"
"Megaface RS-75" available from DIC Corporation
Active component concentration: 40 wt %
(Fluorine-Containing Urethane Acrylate Other than Urethane Acrylate
(S): Fluorine-Containing Polyether-Based Urethane Acrylate)
"602A"
"Ftergent 602A" available from Neos Co., Ltd.
Active component concentration: about 50 wt %
(Perfluoroalkyl-Based Monomer (T))
"FAAC-6"
"CHEMINOX FAAC-6" available from Unimatec Corporation
Active component concentration: 100 wt %
Fluorine atom concentration: 59.1 wt %
"FAAC-4"
"CHEMINOX FAAC-4" available from Unimatec Corporation
Active component concentration: 100 wt %
Fluorine atom concentration: 53.7 wt %
"V8FM"
"Viscoat 8FM" available from Osaka Organic Chemical Industry
Ltd.
Active component concentration: 100 wt %
Fluorine atom concentration: 50.7 wt %
(Perfluoroalkyl-Based Monomer Other than Perfluoroalkyl-Based
Monomer (T))
"V4F"
"Viscoat 4F" available from Osaka Organic Chemical Industry
Ltd.
Active component concentration: 100 wt %
Fluorine atom concentration: 40.9 wt %
"C10A"
"C10ACRY" available from Exfluor Research Corporation
Active component concentration: 100 wt %
Fluorine atom concentration: 65.2 wt %
(Block Copolymer)
"F606"
"Modiper F606" available from NOF Corporation
Active component concentration: 100 wt %
Perfluoroalkyl group: present
(Meth)acryloyl group: absent
(Perfluoropolyether-Based Oligomer)
"MT70"
"Fomblin MT70" available from Solvay Japan, Ltd.
Active component concentration: 80 wt %
"1203E"
"X-27-1203E" available from Shin-Etsu Chemical Co., Ltd.
Active component concentration: 20 wt %
(Polymerization Initiator)
"819"
"Omnirad 819" available from IGM Resins B.V.
Active component concentration: 100 wt %
"TPO"
"Omnirad TPO" available from IGM Resins B.V.
Active component concentration: 100 wt %
"184"
"Omnirad 184" available from IGM Resins B.V.
Active component concentration: 100 wt %
TABLE-US-00001 TABLE 1 Polymerizable composition Component
Abbreviation A1 A2 A3 A4 A5 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 75.0 75.0 75.0 70.0 (parts by monomer (R)
M280 -- -- -- -- -- weight) Multifunctional acrylate (R2) M300 15.0
15.0 15.0 15.0 15.0 M600 -- -- -- -- -- U-10 -- -- -- -- --
Multifunctional acrylate 5027E -- -- -- -- -- other than (R1) and
(R2) Monofunctional amide monomer AC 10.0 10.0 10.0 10.0 15.0
Reactive diluent E8110R 4.0 -- 4.0 4.0 -- Fluorine-based Urethane
acrylate (S) E8110 4.0 -- 4.0 4.0 -- compound RS-75 -- 4.0 -- --
15.0 Fluorine-containing urethane 602A -- -- -- -- -- acrylate
other than (S) Perfluoroalkyl-based monomer (T) FAAC-6 4.0 4.0 --
-- 4.0 FAAC-4 -- -- 6.0 -- -- V8FM -- -- -- -- --
Perfluoroalkyl-based monomer V4F -- -- -- -- -- other than (T) C10A
-- -- -- -- -- Block copolymer F606 -- -- -- -- --
Perfluoropolyether-based oligomer MT70 -- -- -- -- -- 1203E -- --
-- -- -- Polymerization Acylphosphine oxide-based 819 1.5 1.5 1.5
1.5 1.5 initiator photopolymerization initiator TPO -- -- -- -- --
Alkylphenone-based 184 1.5 1.5 1.5 1.5 1.5 photopolymerization
initiator
TABLE-US-00002 TABLE 2 Polymerizable composition Component
Abbreviation A6 A7 A8 A9 A10 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 75.0 75.0 75.0 75.0 (parts by monomer (R)
M280 -- -- -- -- -- weight) Multifunctional acrylate (R2) M300 15.0
15.0 15.0 15.0 15.0 M600 -- -- -- -- -- U-10 -- -- -- -- --
Multifunctional acrylate 5027E -- -- -- -- -- other than (R1) and
(R2) Monofunctional amide monomer AC 10.0 10.0 10.0 10.0 10.0
Reactive diluent E8110R -- 4.0 4.0 4.0 4.0 Fluorine-based Urethane
acrylate (S) E8110 -- 4.0 4.0 4.0 4.0 compound RS-75 3.0 -- -- --
-- Fluorine-containing urethane 602A -- -- -- -- -- acrylate other
than (S) Perfluoroalkyl-based monomer (T) FAAC-6 4.0 10.0 3.0 4.0
4.0 FAAC-4 -- -- -- -- -- V8FM -- -- -- -- -- Perfluoroalkyl-based
monomer V4F -- -- -- -- -- other than (T) C10A -- -- -- -- -- Block
copolymer F606 -- -- -- 1.0 4.0 Perfluoropolyether-based oligomer
MT70 -- -- -- -- -- 1203E -- -- -- -- -- Polymerization
Acylphosphine oxide-based 819 1.5 1.5 1.5 1.5 1.5 initiator
photopolymerization initiator TPO -- -- -- -- -- Alkylphenone-based
184 1.5 1.5 1.5 1.5 1.5 photopolymerization initiator
TABLE-US-00003 TABLE 3 Polymerizable composition Component
Abbreviation A11 A12 A13 A14 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 75.0 5.0 43.0 (parts by monomer (R) M280 --
-- 70.0 -- weight) Multifunctional acrylate (R2) M300 15.0 15.0
15.0 47.0 M600 -- -- -- -- U-10 -- -- -- -- Multifunctional
acrylate 5027E -- -- -- -- other than (R1) and (R2) Monofunctional
amide monomer AC 10.0 10.0 10.0 10.0 Reactive diluent E8110R 4.0
4.0 4.0 4.0 Fluorine-based Urethane acrylate (S) E8110 4.0 4.0 4.0
4.0 compound RS-75 -- -- -- -- Fluorine-containing urethane 602A --
-- -- -- acrylate other than (S) Perfluoroalkyl-based monomer (T)
FAAC-6 4.0 4.0 4.0 4.0 FAAC-4 -- -- -- -- V8FM -- -- -- --
Perfluoroalkyl-based monomer V4F -- -- -- -- other than (T) C10A --
-- -- -- Block copolymer F606 -- -- -- -- Perfluoropolyether based
oligomer MT70 -- -- -- -- 1203E -- -- -- -- Polymerization
Acylphosphine oxide-based 819 -- 3.0 1.5 1.5 initiator
photopolymerization initiator TPO 1.5 -- -- -- Alkylphenone-based
184 1.5 -- 1.5 1.5 photopolymerization initiator
TABLE-US-00004 TABLE 4 Polymerizable composition Component
Abbreviation A15 A16 A17 A18 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 75.0 80.0 75.0 (parts by monomer (R) M280
-- -- -- 60.0 weight) Multifunctional acrylate (R2) M300 -- -- 15.0
15.0 M600 15.0 -- -- -- U-10 -- 15.0 -- -- Multifunctional acrylate
5027E -- -- -- -- other than (R1) and (R2) Monofunctional amide
monomer AC 10.0 10.0 18.2 23.0 Reactive diluent E8110R 4.0 4.0 --
-- Fluorine-based Urethane acrylate (S) E8110 4.0 4.0 -- --
compound RS-75 -- -- 18.2 4.9 Fluorine-containing urethane 602A --
-- -- -- acrylate other than (S) Perfluoroalkyl-based monomer (T)
FAAC-6 4.0 4.0 12.2 4.8 FAAC-4 -- -- -- -- V8FM -- -- -- --
Perfluoroalkyl-based monomer V4F -- -- -- -- other than (T) C10A --
-- -- -- Block copolymer F606 -- -- -- -- Perfluoropolyether based
oligomer MT70 -- -- -- -- 1203E -- -- -- -- Polymerization
Acylphosphine oxide-based 819 1.5 1.5 2.0 1.0 initiator
photopolymerization initiator TPO -- -- -- -- Alkylphenone-based
184 1.5 1.5 2.0 1.0 photopolymerization initiator
TABLE-US-00005 TABLE 5 Polymerizable composition Component
Abbreviation B1 B2 B3 B4 Amount Polymerizable Bifunctional acrylate
(R1) M282 75.0 75.0 75.0 75.0 (parts by monomer (R) M280 -- -- --
-- weight) Multifunctional acrylate (R2) M300 15.0 15.0 15.0 15.0
M600 -- -- -- -- U-10 -- -- -- -- -- -- -- -- Multifunctional
acrylate 5027E -- -- -- -- other than (R1) and (R2) Monofunctional
amide monomer AC 10.0 10.0 10.0 10.0 Reactive diluent E8110R -- --
-- -- Fluorine-based Urethane acrylate (S) E8110 -- -- -- --
compound RS-75 -- -- 4.0 -- Fluorine-containing urethane 602A -- --
-- -- acrylate other than (S) Perfluoroalkyl-based monomer (T)
FAAC-6 -- 4.0 -- 4.0 FAAC-4 -- -- -- -- V8FM -- -- -- --
Perfluoroalkyl-based monomer V4F -- -- -- -- other than (T) C10A --
-- -- -- Block copolymer F606 -- -- -- -- Perfluoropolyether based
oligomer MT70 -- -- -- 4.0 1203E -- -- -- -- Polymerization
Acylphosphine oxide-based 819 1.5 1.5 1.5 1.5 initiator
photopolymerization initiator TPO -- -- -- -- Alkylphenone-based
184 1.5 1.5 1.5 1.5 photopolymerization initiator
TABLE-US-00006 TABLE 6 Polymerizable composition Component
Abbreviation B5 B6 B7 B8 Amount Polymerizable Bifunctional acrylate
(R1) M282 75.0 75.0 75.0 75.0 (parts by monomer (R) M280 -- -- --
-- weight) Multifunctional acrylate (R2) M300 15.0 15.0 15.0 15.0
M600 -- -- -- -- U-10 -- -- -- -- Multifunctional acrylate 5027E --
-- -- -- other than (R1) and (R2) Monofunctional amide monomer AC
10.0 10.0 10.0 10.0 Reactive diluent E8110R -- -- -- 4.0
Fluorine-based Urethane acrylate (S) E8110 -- -- -- 4.0 compound
RS-75 -- 17.0 2.5 -- Fluorine-containing urethane 602A -- -- -- --
acrylate other than (S) Perfluoroalkyl-based monomer (T) FAAC-6 4.0
4.0 4.0 -- FAAC-4 -- -- -- -- V8FM -- -- -- -- Perfluoroalkyl-based
monomer V4F -- -- -- 4.0 other than (T) C10A -- -- -- -- Block
copolymer F606 -- -- -- -- Perfluoropolyether based oligomer MT70
-- -- -- -- 1203E 4.0 -- -- -- Polymerization Acylphosphine
oxide-based 819 1.5 1.5 1.5 1.5 initiator photopolymerization
initiator TPO -- -- -- -- Alkylphenone-based 184 1.5 1.5 1.5 1.5
photopolymerization initiator
TABLE-US-00007 TABLE 7 Polymerizable composition Component
Abbreviation B9 B10 B11 B12 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 -- 63.0 38.0 (parts by monomer (R) M280 --
-- 30.0 -- weight) Multifunctional acrylate (R2) M300 15.0 15.0 --
55.0 M600 -- -- -- -- U-10 -- -- -- -- Multifunctional acrylate
5027E -- 75.0 -- -- other than (R1) and (R2) Monofunctional amide
monomer AC 10.0 10.0 7.0 7.0 Reactive diluent E8110R 4.0 4.0 4.0
4.0 Fluorine-based Urethane acrylate (S) E8110 4.0 4.0 4.0 4.0
compound RS-75 -- -- -- -- Fluorine-containing urethane 602A -- --
-- -- acrylate other than (S) Perfluoroalkyl-based monomer (T)
FAAC-6 -- 4.0 4.0 4.0 FAAC-4 -- -- -- -- V8FM -- -- -- --
Perfluoroalkyl-based monomer V4F -- -- -- -- other than (T) C10A
4.0 -- -- -- Block copolymer F606 -- -- -- -- Perfluoropolyether
based oligomer MT70 -- -- -- -- 1203E -- -- -- -- Polymerization
Acylphosphine oxide-based 819 1.5 1.5 1.5 1.5 initiator
photopolymerization initiator TPO -- -- -- -- Alkylphenone-based
184 1.5 1.5 1.5 1.5 photopolymerization initiator
TABLE-US-00008 TABLE 8 Polymerizable composition Component
Abbreviation B13 B14 B15 B16 Amount Polymerizable Bifunctional
acrylate (R1) M282 75.0 75.0 75.0 80.0 (parts by monomer (R) M280
-- -- -- -- weight) Multifunctional acrylate (R2) M300 15.0 15.0
15.0 15.0 M600 -- -- -- -- U-10 -- -- -- -- -- -- -- --
Multifunctional acrylate 5027E -- -- -- -- other than (R1) and (R2)
Monofunctional amide monomer AC 10.0 10.0 10.0 19.2 Reactive
diluent E8110R -- -- -- -- Fluorine-based Urethane acrylate (S)
E8110 -- -- -- -- compound RS-75 -- 2.3 4.0 19.2
Fluorine-containing urethane 602A 4.0 -- -- -- acrylate other than
(S) Perfluoroalkyl-based monomer (T) FAAC-6 4.0 2.5 11.0 13.0
FAAC-4 -- -- -- -- V8FM -- -- -- -- Perfluoroalkyl-based monomer
V4F -- -- -- -- other than (T) C10A -- -- -- -- Block copolymer
F606 -- -- -- -- Perfluoropolyether based oligomer MT70 -- -- -- --
1203E -- -- -- -- Polymerization Acylphosphine oxide-based 819 1.5
1.5 1.5 5.0 initiator photopolymerization initiator TPO -- -- -- --
Alkylphenone-based 184 1.5 1.5 1.5 5.0 photopolymerization
initiator
Tables 9 to 16 show the percentages of the components (in terms of
active components) and the ethylene oxide group concentrations in
the polymerizable compositions A1 to A18 and B1 to B16.
TABLE-US-00009 TABLE 9 Polymerizable composition Component A1 A2 A3
A4 A5 Percentage Polymerizable Bifunctional acrylate (R1) 65.22
67.58 64.10 64.10 57.36 (wt %) monomer (R) Multifunctional acrylate
(R2) 13.04 13.51 12.82 12.82 12.30 Multifunctional acrylate -- --
-- -- -- other than (R1) and (R2) Monofunctional amide monomer 8.70
9.01 8.55 8.55 12.30 Reactive diluent 3.48 -- 3.42 3.42 -- Total
90.44 90.10 88.89 88.89 81.96 Fluorine-based Urethane acrylate (S)
3.48 3.60 3.42 3.42 12.30 compound Fluorine-containing urethane --
-- -- -- -- acrylate other than (S) Perfluoroalkyl-based 3.48 3.60
5.13 5.13 3.28 monomer (T) Perfluoroalkyl-based monomer other -- --
-- -- -- than (T) Block copolymer -- -- -- -- --
Perfluoropolyether-based oligomer -- -- -- -- -- Total 6.96 7.20
8.55 8.55 15.58 Polymerization Acylphosphine oxide-based 1.30 1.35
1.28 1.28 1.23 initiator photopolymerization initiator
Alkylphenone-based 1.30 1.35 1.28 1.28 1.23 photopolymerization
initiator Total 2.60 2.70 2.56 2.56 2.46 Ethylene oxide group
concentration (wt %) 37.27 38.62 36.63 36.63 32.78
TABLE-US-00010 TABLE 10 Polymerizable composition Component A6 A7
A8 A9 A10 Percentage Polymerizable Bifunctional acrylate (R1) 68.18
61.98 65.78 64.66 63.03 (wt %) monomer (R) Multifunctional acrylate
(R2) 13.64 12.40 13.16 12.93 12.61 Multifunctional acrylate -- --
-- -- -- other than (R1) and (R2) Monofunctional amide monomer 9.09
8.26 8.77 8.62 8.40 Reactive diluent -- 3.31 3.51 3.45 3.36 Total
90.91 85.95 91.22 89.66 87.40 Fluorine-based Urethane acrylate (S)
2.73 3.31 3.51 3.45 3.36 compound Fluorine-containing urethane --
-- -- -- -- acrylate other than (S) Perfluoroalkyl-based monomer
(T) 3.64 8.26 2.63 3.45 3.36 Perfluoroalkyl-based monomer -- -- --
-- -- other than (T) Block copolymer -- -- -- 0.86 3.36
Perfluoropolyether-based oligomer -- -- -- -- -- Total 6.37 11.57
6.14 7.76 10.08 Polymerization Acylphosphine oxide-based 1.36 1.24
1.32 1.29 1.26 initiator photopolymerization initiator
Alkylphenone-based 1.36 1.24 1.32 1.29 1.26 photopolymerization
initiator Total 2.72 2.48 2.64 2.58 2.52 Ethylene oxide group
concentration (wt %) 38.96 35.42 37.59 36.95 36.02
TABLE-US-00011 TABLE 11 Polymerizable composition Component A11 A12
A13 A14 Percentage Polymerizable Bifunctional acrylate (R1) 65.22
65.22 65.22 37.39 (wt %) monomer (R) Multifunctional acrylate (R2)
13.04 13.04 13.04 40.87 Multifunctional acrylate -- -- -- -- other
than (R1) and (R2) Monofunctional amide monomer 8.70 8.70 8.70 8.70
Reactive diluent 3.48 3.48 3.48 3.48 Total 90.44 90.44 90.44 90.44
Fluorine-based Urethane acrylate (S) 3.48 3.48 3.48 3.48 compound
Fluorine-containing urethane -- -- -- -- acrylate other than (S)
Perfluoroalkyl-based monomer (T) 3.48 3.48 3.48 3.48
Perfluoroalkyl-based monomer -- -- -- -- other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer -- -- -- --
Total 6.96 6.96 6.96 6.96 Polymerization Acylphosphine oxide-based
1.30 2.60 1.30 1.30 initiator photopolymerization initiator
Alkylphenone-based 1.30 -- 1.30 1.30 photopolymerization initiator
Total 2.60 2.60 2.60 2.60 Ethylene oxide group concentration (wt %)
37.27 37.27 48.57 21.37
TABLE-US-00012 TABLE 12 Polymerizable composition Component A15 A16
A17 A18 Percentage Polymerizable Bifunctional acrylate (R1) 65.22
65.22 54.19 73.10 (wt %) monomer (R) Multifunctional acrylate (R2)
13.04 13.04 10.16 8.12 Multifunctional acrylate -- -- -- -- other
than (R1) and (R2) Monofunctional amide monomer 8.70 8.70 12.33
12.45 Reactive diluent 3.48 3.48 -- -- Total 90.44 90.44 76.68
93.67 Fluorine-based Urethane acrylate (S) 3.48 3.48 12.33 2.65
compound Fluorine-containing urethane -- -- -- -- acrylate other
than (S) Perfluoroalkyl-based monomer (T) 3.48 3.48 8.27 2.60
Perfluoroalkyl-based monomer -- -- -- -- other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer -- -- -- --
Total 6.96 6.96 20.60 5.25 Polymerization Acylphosphine oxide-based
1.30 1.30 1.36 0.54 initiator photopolymerization initiator
Alkylphenone-based 1.30 1.30 1.36 0.54 photopolymerization
initiator Total 2.60 2.60 2.72 1.08 Ethylene oxide group
concentration (wt %) 37.27 37.27 30.97 47.81
TABLE-US-00013 TABLE 13 Polymerizable composition Component B1 B2
B3 B4 Percentage Polymerizable Bifunctional acrylate (R1) 72.81
70.09 70.09 67.58 (wt %) monomer (R) Multifunctional acrylate (R2)
14.56 14.02 14.02 13.51 Multifunctional acrylate -- -- -- -- other
than (R1) and (R2) Monofunctional amide monomer 9.71 9.35 9.35 9.01
Reactive diluent -- -- -- -- Total 97.08 93.46 93.46 90.10
Fluorine-based Urethane acrylate (S) -- -- 3.74 -- compound
Fluorine-containing urethane -- -- -- -- acrylate other than (S)
Perfluoroalkyl-based monomer (T) -- 3.74 -- 3.60
Perfluoroalkyl-based monomer -- -- -- -- other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer -- -- --
3.60 Total -- 3.74 3.74 7.20 Polymerization Acylphosphine
oxide-based 1.46 1.40 1.40 1.35 initiator photopolymerization
initiator Alkylphenone-based 1.46 1.40 1.40 1.35
photopolymerization initiator Total 2.92 2.80 2.80 2.70 Ethylene
oxide group concentration (wt %) 41.61 40.05 40.05 38.62
TABLE-US-00014 TABLE 14 Polymerizable composition Component B5 B6
B7 B8 Percentage Polymerizable Bifunctional acrylate (R1) 67.58
60.48 68.50 65.22 (wt %) monomer (R) Multifunctional acrylate (R2)
13.51 12.10 13.70 13.04 Multifunctional acrylate -- -- -- -- other
than (R1) and (R2) Monofunctional amide monomer 9.01 8.06 9.13 8.70
Reactive diluent -- -- -- 3.48 Total 90.10 80.64 91.33 90.44
Fluorine-based Urethane acrylate (S) -- 13.71 2.28 3.48 compound
Fluorine-containing urethane -- -- -- -- acrylate other than (S)
Perfluoroalkyl-based monomer (T) 3.60 3.23 3.65 --
Perfluoroalkyl-based monomer -- -- -- 3.48 other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer 3.60 -- --
-- Total 7.20 16.94 5.93 6.96 Polymerization Acylphosphine
oxide-based 1.35 1.21 1.37 1.30 initiator photopolymerization
initiator Alkylphenone-based 1.35 1.21 1.37 1.30
photopolymerization initiator Total 2.70 2.42 2.74 2.60 Ethylene
oxide group concentration (wt %) 38.62 34.56 39.14 37.27
TABLE-US-00015 TABLE 15 Polymerizable composition Component B9 B10
B11 B12 Percentage Polymerizable Bifunctional acrylate (R1) 65.22
-- 80.87 33.04 (wt %) monomer (R) Multifunctional acrylate (R2)
13.04 13.04 -- 47.83 Multifunctional acrylate -- 65.22 -- -- other
than (R1) and (R2) Monofunctional amide monomer 8.70 8.70 6.09 6.09
Reactive diluent 3.48 3.48 3.48 3.48 Total 90.44 90.44 90.44 90.44
Fluorine-based Urethane acrylate (S) 3.48 3.48 3.48 3.48 compound
Fluorine-containing urethane -- -- -- -- acrylate other than (S)
Perfluoroalkyl-based monomer (T) -- 3.48 3.48 3.48
Perfluoroalkyl-based monomer 3.48 -- -- -- other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer -- -- -- --
Total 6.96 6.96 6.96 6.96 Polymerization Acylphosphine oxide-based
1.30 1.30 1.30 1.30 initiator photopolymerization initiator
Alkylphenone-based 1.30 1.30 1.30 1.30 photopolymerization
initiator Total 2.60 2.60 2.60 2.60 Ethylene oxide group
concentration (wt %) 37.27 35.03 51.06 18.88
TABLE-US-00016 TABLE 16 Polymerizable composition Component B13 B14
B15 B16 Percentage Polymerizable Bifunctional acrylate (R1) 67.58
69.58 63.57 51.14 (wt %) monomer (R) Multifunctional acrylate (R2)
13.51 13.91 12.71 9.59 Multifunctional acrylate -- -- -- -- other
than (R1) and (R2) Monofunctional amide monomer 9.01 9.28 8.47
12.28 Reactive diluent -- -- -- -- Total 90.10 92.77 84.75 73.01
Fluorine-based Urethane acrylate (S) -- 2.13 3.39 12.28 compound
Fluorine-containing urethane 3.60 -- -- -- acrylate other than (S)
Perfluoroalkyl-based monomer (T) 3.60 2.32 9.32 8.31
Perfluoroalkyl-based monomer -- -- -- -- other than (T) Block
copolymer -- -- -- -- Perfluoropolyether-based oligomer -- -- -- --
Total 7.20 4.45 12.71 20.59 Polymerization Acylphosphine
oxide-based 1.35 1.39 1.27 3.20 initiator photopolymerization
initiator Alkylphenone-based 1.35 1.39 1.27 3.20
photopolymerization initiator Total 2.70 2.78 2.54 6.40 Ethylene
oxide group concentration (wt %) 38.62 39.76 36.33 29.22
Example 1
An antifouling film of Example 1 was produced by the following
method.
(A) Release Treatment of Die
A release agent was applied to a surface of a die. The thickness of
the release agent was 5 nm. The surface coated with the release
agent of a die had a contact angle (static contact angle) with
water of about 130.degree..
(B) Application of Polymerizable Composition
The polymerizable composition A1 was applied to a surface of the
substrate. The thickness of the polymerizable composition A1 was 35
.mu.m.
(C) Formation of Uneven Structure
The substrate was pushed to the surface coated with the release
agent of the die with the polymerizable composition A1 in between.
As a result, an uneven structure was formed on the surface (the
surface remote from the substrate) of the polymerizable composition
A1.
(D) Formation of Polymer Layer
The polymerizable composition A1 was irradiated with ultraviolet
rays (dose: 1 J/cm.sup.2) from the substrate side, so that the
polymerizable composition A1 was cured. As a result, a polymer
layer was formed.
(E) Die Removal
The die was removed from the polymer layer. The polymer layer was
then irradiated with ultraviolet rays (dose: 1 J/cm.sup.2) from the
side remote from the substrate, so that the polymer layer was
further cured. As a result, an antifouling film was completed.
Then, die transferring (a series of the processes (B) to (E)) was
repeated 100 times, whereby antifouling films were continuously
produced. The antifouling film (100th antifouling film) produced in
the 100th die transferring was obtained as the antifouling film of
Example 1.
The polymer layer in the antifouling film of Example 1 had a
thickness of 12 .mu.m.
The surface specifications of the antifouling film of Example 1
were as follows.
Shape of projections: temple-bell-like shape
Average pitch of projections: 200 nm
Average height of projections: 200 nm
Average aspect ratio of projections: 1.0
The surface specifications of the antifouling film were evaluated
using a scanning electron microscope "S-4700" from Hitachi
High-Technologies Corp. For the evaluation, osmium(VIII) oxide from
Fujifilm Wako Pure Chemical Corporation was applied (thickness: 5
nm) to the surface (the surface remote from the substrate) of the
polymer layer using an osmium coater "Neoc-ST" from Meiwafosis Co.,
Ltd.
Examples 2 to 19 and Comparative Examples 1 to 16
An antifouling film (100th antifouling film) of each example was
produced in the same manner as in Example 1, except that production
conditions were changed according to Tables 17 to 24.
[Evaluations]
The antifouling films of the examples were subjected to the
following evaluations. Tables 17 to 24 show the results.
<Transparency>
For the transparency, the transparency of the polymerizable
composition was evaluated. Specifically, the polymerizable
composition was placed in a clear test tube and left to stand in an
environment with a temperature of 30.degree. C. and a humidity of
85% for one week. Then, the condition of the polymerizable
composition was visually observed in an environment with an
illuminance of 100 l.times. (fluorescent lamp). The evaluation
criteria were as follows.
Good: The composition was transparent or slightly cloudy.
Fair: The composition was slightly cloudy, but no precipitate was
observed even after it was further left to stand for one day.
Poor: The composition was cloudy, and precipitates were observed
after it was further left to stand for one day.
A higher transparency of the polymerizable composition was
determined to show a higher compatibility of the components with
each other in the polymerizable composition.
<Antifouling Properties>
For the antifouling properties, the oil repellency and the ease of
wiping off fingerprints of the antifouling film were evaluated.
(Oil Repellency)
Hexadecane (about 10 .mu.l of liquid droplets) was dropped on the
surface (the surface remote from the substrate) of the polymer
layer of the antifouling film, and the contact angle (static
contact angle) was determined after 1 second, 10 minutes, and 60
minutes from the dropping. The cases with a contact angle with
hexadecane of 30.degree. or greater were evaluated as having
excellent oil repellency.
The contact angles were each the average value of contact angles
determined at the following three points by the .theta./2 method
(.theta./2=arctan (h/r), wherein .theta.: contact angle, r: radius
of droplet, h: height of droplet) using a portable contact angle
meter "PCA-1" from Kyowa Interface Science Co., Ltd. The first
measurement point selected was the central portion of the
antifouling film. The second and third measurement points were two
points that were 20 mm or more apart from the first measurement
point and were point-symmetrical to each other about the first
measurement point.
(Ease of Wiping Off Fingerprints)
First, a black acrylic plate "Acrylite EX-502" available from
Mitsubishi Rayon Co., Ltd. was attached to the surface remote from
the polymer layer of the substrate of the antifouling film with an
optical adhesive layer in between. Next, "Bemcot.RTM. S-2",
available from Asahi Kasei Fibers Corp. was impregnated with 0.1 ml
of an artificial contamination liquid available from Isekyu Co.,
Ltd. as an assumed fingerprint. The artificial contamination liquid
was then applied to a finger in a rubber glove. Then, the
artificial contamination liquid was applied to the surface (the
surface remote from the substrate) of the polymer layer of the
antifouling film with the finger. After 10 minutes and 60 minutes
from the application of the artificial contamination liquid, the
surface was rubbed 10 times in a reciprocating motion using "Bemcot
S-2" from Asahi Kasei Fibers Corp. Whether the artificial
contamination liquid was wiped off or not was visually observed in
an environment with an illuminance of 100 l.times. (fluorescent
lamp). The evaluation criteria were as follows.
Good: The artificial contamination liquid was completely wiped off
and no wiping residue was observed.
Fair: The artificial contamination liquid was not obvious, but
slight wiping residue was observed when the light from the
fluorescent lamp was reflected on the surface.
Poor: Slight wiping residue was observed without reflecting the
light from the fluorescent lamp on the surface.
Bad: The artificial contamination liquid was not wiped off at all:
wiping residue was obviously observed without reflecting the light
from the fluorescent lamp on the surface.
The cases evaluated as good or fair were considered as having
excellent ease of wiping off fingerprints.
<Rubbing Resistance>
A black acrylic plate "Acrylite EX-502" available from Mitsubishi
Rayon Co., Ltd. was attached to the surface remote from the polymer
layer of the substrate of the antifouling film with an optical
adhesive layer in between. The surface (the surface remote from the
substrate) of the polymer layer of the antifouling film was
irradiated with light from a light source from a polar angle of
5.degree. and the specular spectral reflectance at an incident
angle of 5.degree. was measured. The reflectance was measured with
a spectrophotometer "UV-3100PC" from Shimadzu Corporation within
the wavelength range of 380 to 780 nm. The average reflectance
within the wavelength range of 450 to 650 nm was calculated based
on the measurement results. The average reflectance is referred to
as Reflectance F1 (unit: %).
The surface (the surface remote from the substrate) of the polymer
layer was rubbed 10 times in a reciprocating motion with "Bemcot
Labo.RTM." from Asahi Kasei Fibers Corp. The specular spectral
reflectance at an incident angle of 5.degree. of the antifouling
film was measured by the same procedure as described above. The
average reflectance within the wavelength range of 450 to 650 nm
was calculated based on the measurement results. The average
reflectance is referred to as Reflectance F2 (unit: %).
Based on Reflectance F1 and Reflectance F2 determined as described
above, the change rate ".DELTA.F" (unit: %) of the reflectance was
calculated according to the following formula (Y).
.DELTA.F=|100.times.(Reflectance F2-Reflectance F1)/Reflectance F1|
(Y)
The evaluation criteria were as follows.
Good: .DELTA.F.ltoreq.15
Fair: 15<.DELTA.F<30
Poor: .DELTA.F.gtoreq.30 The cases evaluated as good or fair were
considered as having excellent rubbing resistance at which the
antifouling film (polymer layer) did not appear white.
TABLE-US-00017 TABLE 17 Example 1 Example 2 Example 3 Example 4
Example 5 Production Polymerizable composition A1 A2 A3 A4 A5
conditions UV irradiation after die removal Present Present Present
Present Present Evaluation Polymerizable Transparency Good Good
Good Good Fair composition Antifouling Antifouling Oil Contact
angle 1 sec. 93.2 92.8 91.4 89.3 93.1 film properties repellency
with hexadecane 10 min. 91.5 90.9 84.3 80.7 91.4 (.degree.) 60 min.
88.6 87.7 67.2 48.2 90.1 Ease of wiping off 10 min. Good Good Good
Good Good fingerprints 60 min. Good Good Fair Fair Good Rubbing
resistance Good Good Good Good Fair
TABLE-US-00018 TABLE 18 Example 6 Example 7 Example 8 Example 9
Example 10 Production Polymerizable composition A6 A7 A8 A9 A10
conditions UV irradiation after die removal Present Present Present
Present Present Evaluation Polymerizable Transparency Good Fair
Good Fair Fair composition Antifouling Antifouling Oil Contact
angle 1 sec. 83.3 95.7 83.3 95.2 95.4 film properties repellency
with hexadecane 10 min. 79.6 93.3 75.2 93.3 93.0 (.degree.) 60 min.
61.2 92.5 59.8 92.1 92.2 Ease of wiping off 10 min. Good Good Good
Good Good fingerprints 60 min. Fair Good Fair Good Good Rubbing
resistance Good Good Fair Good Good
TABLE-US-00019 TABLE 19 Exam- Exam- Exam- Exam- Exam- ple 11 ple 12
ple 13 ple 14 ple 15 Production Polymerizable composition A11 A12
A1 A13 A14 conditions UV irradiation after die removal Present
Present Absent Present Present Evaluation Polymerizable
Transparency Good Good Good Fair Good composition Antifouling
Antifouling Oil Contact angle 1 sec. 92.4 90.1 90.4 94.1 84.5 film
properties repellency with hexadecane 10 min. 90.8 82.3 85.3 92.3
80.2 (.degree.) 60 min. 87.3 65.2 68.2 90.5 64.8 Ease of wiping off
10 min. Good Good Good Good Good fingerprints 60 min. Good Fair
Fair Good Fair Rubbing resistance Good Good Good Good Good
TABLE-US-00020 TABLE 20 Example 16 Example 17 Example 18 Example 19
Production Polymerizable composition A15 A16 A17 A18 conditions UV
irradiation after die removal Present Present Present Present
Evaluation Polymerizable Transparency Good Fair Fair Good
composition Antifouling Antifouling Oil Contact angle 1 sec. 91.3
82.1 94.8 80.4 film properties repellency with hexadecane 10 min.
90.1 78.2 92.3 75.6 (.degree.) 60 min. 85.2 62.3 91.8 57.8 Ease of
wiping off 10 min. Good Good Good Good fingerprints 60 min. Good
Fair Good Fair Rubbing resistance Good Good Fair Fair
TABLE-US-00021 TABLE 21 Comparative Comparative Comparative
Comparative Example 1 Example 2 Example 3 Example 4 Production
Polymerizable composition B1 B2 B3 B4 conditions UV irradiation
after die removal Present Present Present Present Evaluation
Polymerizable Transparency Good Good Good Good composition
Antifouling Antifouling Oil Contact angle 1 sec. 15.3 30.6 45.3
90.2 film properties repellency with hexadecane 10 min. 11.3 23.3
37.4 80.5 (.degree.) 60 min. 10.8 22.3 28.1 26.3 Ease of wiping off
10 min. Bad Poor Fair Good fingerprints 60 min. Bad Poor Poor Poor
Rubbing resistance Poor Fair Fair Good
TABLE-US-00022 TABLE 22 Comparative Comparative Comparative
Comparative Example 5 Example 6 Example 7 Example 8 Production
Polymerizable composition B5 B6 B7 B8 conditions UV irradiation
after die removal Present Present Present Present Evaluation
Polymerizable Transparency Good Poor Good Good composition
Antifouling Antifouling Oil Contact angle 1 sec. 88.8 -- 52.8 49.2
film properties repellency with hexadecane 10 min. 76.5 -- 40.8
37.1 (.degree.) 60 min. 24.8 -- 22.4 22.1 Ease of wiping off 10
min. Good -- Fair Fair fingerprints 60 min. Poor -- Poor Poor
Rubbing resistance Good -- Fair Good
TABLE-US-00023 TABLE 23 Comparative Comparative Comparative
Comparative Example 9 Example 10 Example 11 Example 12 Production
Polymerizable composition B9 B10 B11 B12 conditions UV irradiation
after die removal Present Present Present Present Evaluation
Polymerizable Transparency Poor Poor Poor Good composition
Antifouling Antifouling Oil Contact angle 1 sec. -- -- -- 78.6 film
properties repellency with hexadecane 10 min. -- -- -- 67.3
(.degree.) 60 min. -- -- -- 28.1 Ease of wiping off 10 min. -- --
-- Fair fingerprints 60 min. -- -- -- Poor Rubbing resistance -- --
-- Good
TABLE-US-00024 TABLE 24 Comparative Comparative Comparative
Comparative Example 13 Example 14 Example 15 Example 16 Production
Polymerizable composition B13 B14 B15 B16 conditions UV irradiation
after die removal Present Present Present Present Evaluation
Polymerizable Transparency Good Good Poor Fair composition
Antifouling Antifouling Oil Contact angle 1 sec. 87.5 71.3 -- 92.8
film properties repellency with hexadecane 10 min. 72.1 39.2 --
91.8 (.degree.) 60 min. 27.3 28.2 -- 90.2 Ease of wiping off 10
min. Good Fair -- -- fingerprints 60 min. Poor Poor -- -- Rubbing
resistance Good Fair -- Poor
Tables 17 to 20 show that, in Examples 1 to 19, the antifouling
properties of the antifouling films were kept high even after 60
minutes and thus long-term high antifouling properties were
achieved. Also, the antifouling films of Examples 1 to 19 had
excellent rubbing resistance.
Tables 21 to 24 show that Comparative Examples 1 to 16 failed to
provide an antifouling film having excellent rubbing resistance and
long-term high antifouling properties.
In Comparative Example 1, the polymerizable composition contained
no fluorine-based compound. Thus, the antifouling properties of the
antifouling film were low from an initial stage, which prevented
achievement of long-term high antifouling properties. Also, in
Comparative Example 1, the polymerizable composition had a
polymerizable monomer (R) content of higher than 95 wt % in terms
of active components, which reduced the rubbing resistance of the
antifouling film.
In Comparative Example 2, the polymerizable composition contained
as a fluorine-based compound the perfluoroalkyl-based monomer (T)
alone, which prevented the antifouling film from having long-term
high antifouling properties.
In Comparative Example 3, the polymerizable composition contained
as a fluorine-based compound the urethane acrylate (S) alone, which
prevented the antifouling film from having long-term high
antifouling properties.
In Comparative Examples 4 and 5, although the polymerizable
composition contained as a fluorine-based compound the
perfluoroalkyl-based monomer (T), the polymerizable composition
further contained not the urethane acrylate (S) but a
perfluoropolyether-based oligomer, which prevented the antifouling
film from having long-term high antifouling properties.
In Comparative Example 6, the polymerizable composition, having a
urethane acrylate (S) content of higher than 12.5 wt % in terms of
active components, was cloudy, which resulted in reduced
transparency (whitening) of the antifouling film (polymer layer).
Accordingly, evaluations for the antifouling properties and the
rubbing resistance were not performed.
In Comparative Example 7, the polymerizable composition had a
urethane acrylate (S) content of lower than 2.5 wt % in terms of
active components, which prevented the antifouling film from having
long-term high antifouling properties.
In Comparative Example 8, although the polymerizable composition
contained as a fluorine-based compound the urethane acrylate (S),
the polymerizable composition further contained not the
perfluoroalkyl-based monomer (T) but a perfluoroalkyl-based monomer
having a fluorine atom concentration of lower than 50 wt %, which
prevented the antifouling film from having long-term high
antifouling properties.
In Comparative Example 9, although the polymerizable composition
contained as a fluorine-based compound the urethane acrylate (S),
the polymerizable composition further contained not the
perfluoroalkyl-based monomer (T) but a perfluoroalkyl-based monomer
having a fluorine atom concentration of higher than 60 wt %. The
polymerizable composition was thus cloudy, which resulted in
reduced transparency (whitening) of the antifouling film (polymer
layer). Accordingly, evaluations for the antifouling properties and
the rubbing resistance were not performed.
In Comparative Example 10, although the polymerizable composition
contained as the polymerizable monomer (R) the multifunctional
acrylate (R2), the polymerizable composition further contained not
the bifunctional acrylate (R1) but a multifunctional acrylate
containing an ethylene oxide group. The polymerizable composition
was thus cloudy, which resulted in reduced transparency (whitening)
of the antifouling film (polymer layer). Accordingly, evaluations
for the antifouling properties and the rubbing resistance were not
performed.
In Comparative Example 11, the polymerizable composition, having an
ethylene oxide group concentration of higher than 50 wt %, was
cloudy, which resulted in reduced transparency (whitening) of the
antifouling film (polymer layer). Accordingly, evaluations for the
antifouling properties and the rubbing resistance were not
performed.
In Comparative Example 12, the polymerizable composition had an
ethylene oxide group concentration of lower than 20 wt %, which
prevented the antifouling film from having long-term high
antifouling properties.
In Comparative Example 13, although the polymerizable composition
contained as a fluorine-based compound the perfluoroalkyl-based
monomer (T), the polymerizable composition further contained not
the urethane acrylate (S) but a fluorine-containing polyether-based
urethane acrylate, which prevented the antifouling film from having
long-term high antifouling properties.
In Comparative Example 14, the polymerizable composition had a
urethane acrylate (S) content of lower than 2.5 wt % in terms of
active components and a perfluoroalkyl-based monomer (T) content of
lower than 2.5 wt % in terms of active components, which prevented
the antifouling film from having long-term high antifouling
properties.
In Comparative Example 15, the polymerizable composition, having a
perfluoroalkyl-based monomer (T) content of higher than 9 wt % in
terms of active components, was cloudy, which resulted in reduced
transparency (whitening) of the antifouling film (polymer layer).
Accordingly, evaluations for the antifouling properties and the
rubbing resistance were not performed.
In Comparative Example 16, the polymerizable composition had a
polymerizable monomer (R) content of lower than 75 wt % in terms of
active components, which reduced the rubbing resistance of the
antifouling film.
[Additional Remarks]
An aspect of the present invention may be an antifouling film
including: a substrate; and a polymer layer disposed on a surface
of the substrate and including on a surface thereof an uneven
structure provided with projections at a pitch not longer than a
wavelength of visible light, the polymer layer being a cured
product of a polymerizable composition, the polymerizable
composition containing, in terms of active components, 75 to 95 wt
% of a polymerizable monomer, 2.5 to 12.5 wt % of a urethane
acrylate containing fluorine and an ester, and 2.5 to 9 wt % of a
perfluoroalkyl-based monomer containing one (meth)acryloyl group
for each molecule, the polymerizable monomer containing a
bifunctional acrylate that contains an ethylene oxide group and a
multifunctional acrylate that contains no ethylene oxide group, the
perfluoroalkyl-based monomer having a fluorine atom concentration
of 50 to 60 wt %, the polymerizable composition having an ethylene
oxide group concentration of 20 to 50 wt %. This aspect achieves an
antifouling film having excellent rubbing resistance and long-term
high antifouling properties.
In the aspect of the present invention, the multifunctional
acrylate may contain 3 to 6 functional groups. This embodiment can
sufficiently increase the compatibility of the polymerizable
monomer with other component(s) (e.g., fluorine-based compound) in
the polymerizable composition and results in sufficiently increased
transparency of the antifouling film (the polymer layer). This
embodiment can also prevent an excessive increase in crosslinking
density of the polymer layer, allows easy concentration of fluorine
atoms in the fluorine-based compounds on a surface (the surface
remote from the substrate) of the polymer layer, and tend to
achieve an antifouling film having long-term high antifouling
properties.
In the aspect of the present invention, the polymerizable monomer
may further contain a monofunctional amide monomer. This embodiment
can increase the compatibility of the polymerizable monomer with
the fluorine-based compounds, which allows easy concentration of
fluorine atoms in the fluorine-based compounds on the surface (the
surface remote from the substrate) of the polymer layer and thus
sufficiently increases the antifouling properties of the
antifouling film. This embodiment can also inhibit shrinkage during
curing of the polymerizable composition and increase the cohesion
with the substrate, and thus can increase the adhesion between the
polymer layer and the substrate.
In the aspect of the present invention, the polymerizable
composition may contain 1 to 15 wt % of the monofunctional amide
monomer in terms of active components. This embodiment can
sufficiently increase the adhesion between the polymer layer and
the substrate. This embodiment can also sufficiently increase the
antifouling properties of the antifouling film. Furthermore, this
embodiment can sufficiently increase the rubbing resistance of the
antifouling film.
In the aspect of the present invention, the polymerizable
composition may further contain a block copolymer containing a
fluorine segment and a non-fluorine segment. This embodiment allows
the non-fluorine segment to function as a compatible segment having
compatibility with other component(s) in the polymerizable
composition and allows concentration of the fluorine segment
(fluorine atoms derived from the fluorine segment) on the surface
(the surface remote from the substrate) of the polymer layer. This
reduces the surface free energy of the polymer layer and
sufficiently increases the antifouling properties of the
antifouling film. Furthermore, the block copolymer tends to be
fixed in the polymer layer by the compatible-segment function of
the non-fluorine segment, which tends to impart long-term high
antifouling properties to the antifouling film.
In the aspect of the present invention, the polymerizable
composition may contain 0.1 to 5 wt % of the block copolymer in
terms of active components. This embodiment can sufficiently
increase the antifouling properties of the antifouling film. This
embodiment can also increase the compatibility of the block
copolymer with other component(s) in the polymerizable composition
and result in sufficiently increased transparency of the
antifouling film (the polymer layer).
In the aspect of the present invention, the polymerizable
composition may further contain a photopolymerization initiator,
and the photopolymerization initiator may contain an acylphosphine
oxide-based photopolymerization initiator and an alkylphenone-based
photopolymerization initiator. This embodiment can significantly
increase the curability of the polymerizable composition, promote
curing (significantly reduces uncured part) of the entire polymer
layer (including the surface close to the substrate and the surface
remote from the substrate), and thus resultantly allows easy
concentration of fluorine atoms in the fluorine-based compounds on
the surface (the surface remote from the substrate) of the polymer
layer.
In the aspect of the present invention, the polymer layer may have
a thickness of 5 to 20 .mu.m. This embodiment allows easy
concentration of fluorine atoms in the fluorine-based compounds on
the surface (the surface remote from the substrate) of the polymer
layer.
In the aspect of the present invention, the projections may be
disposed at an average pitch of 100 to 400 nm. This embodiment can
sufficiently prevent optical phenomena such as moire and
iridescence.
In the aspect of the present invention, the projections may have an
average height of 50 to 600 nm. This embodiment can achieve both a
preferred average height and a preferred average aspect ratio of
the projections.
In the aspect of the present invention, the projections may have an
average aspect ratio of 0.8 to 1.5. This embodiment can
sufficiently prevent optical phenomena such as moire and
iridescence and achieves excellent antireflective properties. This
embodiment can also sufficiently prevent occurrence of sticking and
deterioration of die transferring condition in formation of an
uneven structure, which are caused by poor processability of the
uneven structure.
Another aspect of the present invention may be a polymerizable
composition including in terms of active components: 75 to 95 wt %
of a polymerizable monomer; 2.5 to 12.5 wt % of a urethane acrylate
containing fluorine and an ester; and 2.5 to 9 wt % of a
perfluoroalkyl-based monomer containing one (meth)acryloyl group
for each molecule, the polymerizable monomer containing a
bifunctional acrylate that contains an ethylene oxide group and a
multifunctional acrylate that contains no ethylene oxide group, the
perfluoroalkyl-based monomer having a fluorine atom concentration
of 50 to 60 wt %, the polymerizable composition having an ethylene
oxide group concentration of 20 to 50 wt %. This aspect achieves a
polymerizable composition for providing a polymer layer of an
antifouling film of an aspect of the present invention.
In another aspect of the present invention, the multifunctional
acrylate may contain 3 to 6 functional groups.
In another aspect of the present invention, the polymerizable
monomer may further contain a monofunctional amide monomer.
In another aspect of the present invention, the polymerizable
composition may contain 1 to 15 wt % of the monofunctional amide
monomer in terms of active components.
In another aspect of the present invention, the polymerizable
composition may further contain a block copolymer containing a
fluorine segment and a non-fluorine segment.
In another aspect of the present invention, the polymerizable
composition may contain 0.1 to 5 wt % of the block copolymer in
terms of active components.
In another aspect of the present invention, the polymerizable
composition may further contain a photopolymerization initiator,
and the photopolymerization initiator may contain an acylphosphine
oxide-based photopolymerization initiator and an alkylphenone-based
photopolymerization initiator.
* * * * *